diff --git a/crates/forms/README.md b/crates/forms/README.md
index 6126dc1cbd..67ca3b3bfb 100644
--- a/crates/forms/README.md
+++ b/crates/forms/README.md
@@ -75,6 +75,12 @@ let cells: Vec<table::Cell> = grid.cells_for(names)?;      // "Table1_1", "Table
   original entry is preserved. Positive limits still apply.
 - Values are validated (options, `MaxLen`, single vs multi-select, NoToggleToOff, read-only) and a
   failed call changes nothing.
+- Native AF recognition stops at the first genuine matching function call. If its arguments
+  are unsupported, the complete action remains a custom script for the caller's `Scripts`
+  interpreter; a later literal call must not replace the original conditional validation.
+  Async for-of loop headers and bodies do not expose AF-looking text inside regex literals.
+- Moving choice fields preserves their own options rather than copying an ancestor's `/Opt`;
+  inherited check-box and radio-button export mappings remain intact.
 - `FieldProps::appearance` applies a `LookPatch` independently to each widget. `None` keeps
   a property; `Some(None)` removes a border/fill colour. Unchanged `/DA`, custom font resources,
   widget-specific `/DA` overrides, indirect `/MK` and `/BS` contents, dash arrays and unknown
diff --git a/crates/forms/src/af/calc.rs b/crates/forms/src/af/calc.rs
index 5c8098dfbb..1c3724ef4a 100644
--- a/crates/forms/src/af/calc.rs
+++ b/crates/forms/src/af/calc.rs
@@ -19,13 +19,21 @@ pub(super) enum Js {
 type Token = (Range<usize>, Js);
 
 /// Words after which `/` starts a regular expression instead of dividing.
-const BEFORE_REGEX: [&str; 13] = ["return", "typeof", "case", "do", "else", "in", "of", "new", "delete", "void", "throw", "instanceof", "yield"];
+const BEFORE_REGEX: [&str; 12] = ["return", "typeof", "case", "do", "else", "in", "new", "delete", "void", "throw", "instanceof", "yield"];
 
 /// Words whose condition, in parentheses, comes before a statement, so a `/` after it starts a
 /// regular expression. The `while` that ends a `do` loop counts too: the loop ends at its `)`, so
 /// a `/` after it starts the next statement, and can't divide.
 const BEFORE_CONDITION: [&str; 4] = ["if", "while", "for", "with"];
 
+/// Context of an open delimiter. Only the left side of a for header can introduce `of`.
+#[derive(Clone, Copy)]
+enum Delimiter {
+    Group,
+    Condition,
+    For { left: bool },
+}
+
 /// Whether a line ends at `s[j]`: JavaScript ends one at `\n`, `\r`, U+2028 and U+2029.
 fn line_ends_at(s: &[u8], j: usize) -> bool {
     matches!(s.get(j..), Some([b'\n' | b'\r', ..] | [0xE2, 0x80, 0xA8 | 0xA9, ..]))
@@ -46,10 +54,11 @@ pub(super) fn js_tokens(js: &str) -> (Vec<Token>, Vec<Range<usize>>) {
     // Where a regular expression that never ended stopped being read: every `/` before it
     // divides, so a line of them is read once, not once for each.
     let mut divides_until = 0;
-    // For each `(` still open, whether it opened the condition of `if`, `while`, `for` or
-    // `with`; and whether the last token is the `)` that closed one.
-    let mut conditions: Vec<bool> = Vec::new();
+    // Nested groups hide the surrounding for header: an `of` in a destructuring default
+    // or nested expression is an identifier, not the for-of separator.
+    let mut delimiters: Vec<(char, Delimiter)> = Vec::new();
     let mut after_condition = false;
+    let mut after_for_of = false;
     'scan: while let Some(&c) = s.get(i) {
         let start = i;
         let token = match c {
@@ -90,7 +99,12 @@ pub(super) fn js_tokens(js: &str) -> (Vec<Token>, Vec<Range<usize>>) {
                 loop {
                     match s.get(j) {
                         None => break 'scan,
-                        Some(b'\\') => j += 2,
+                        Some(b'\\') => {
+                            let Some(step) = js.get(j + 1..).and_then(|r| r.chars().next()).map(char::len_utf8) else {
+                                break 'scan;
+                            };
+                            j += 1 + step;
+                        }
                         Some(b'`') => break,
                         Some(_) => j += 1,
                     }
@@ -98,7 +112,7 @@ pub(super) fn js_tokens(js: &str) -> (Vec<Token>, Vec<Range<usize>>) {
                 i = j + 1;
                 Js::Other
             }
-            b'/' if i >= divides_until && regex_may_follow(js, &out, after_condition) => {
+            b'/' if i >= divides_until && regex_may_follow(js, &out, after_condition, after_for_of) => {
                 // A regular expression ends at a `/` outside a class; a line break first means it
                 // was a division after all.
                 let (mut j, mut class) = (i + 1, false);
@@ -106,7 +120,14 @@ pub(super) fn js_tokens(js: &str) -> (Vec<Token>, Vec<Range<usize>>) {
                     match s.get(j) {
                         None => break None,
                         Some(_) if line_ends_at(s, j) => break None,
-                        Some(b'\\') => j += 2,
+                        Some(b'\\') => {
+                            if s.get(j + 1).is_none() || line_ends_at(s, j + 1) {
+                                j += 1;
+                                break None;
+                            }
+                            let step = js.get(j + 1..).and_then(|r| r.chars().next()).map_or(1, char::len_utf8);
+                            j += 1 + step;
+                        }
                         Some(b'/') if !class => break Some(j),
                         Some(b) => {
                             class = match b {
@@ -133,6 +154,16 @@ pub(super) fn js_tokens(js: &str) -> (Vec<Token>, Vec<Range<usize>>) {
                     }
                 }
             }
+            b'+' | b'-'
+                if s.get(i + 1) == Some(&c)
+                    && !regex_may_follow(js, &out, after_condition, after_for_of)
+                    && out.last().is_some_and(|(range, _)| !(range.end..i).any(|j| line_ends_at(s, j))) =>
+            {
+                // Postfix update ends an expression: a following slash divides. A line
+                // terminator forbids postfix syntax, including one inside a comment.
+                i += 2;
+                Js::Other
+            }
             _ if c.is_ascii_digit() => {
                 while word(i) || s.get(i) == Some(&b'.') {
                     i += 1;
@@ -150,38 +181,88 @@ pub(super) fn js_tokens(js: &str) -> (Vec<Token>, Vec<Range<usize>>) {
                 Js::Punct(char::from(c))
             }
         };
-        after_condition = match token {
-            Js::Punct('(') => {
-                conditions.push(opens_condition(js, &out));
-                false
-            }
-            Js::Punct(')') => conditions.pop().unwrap_or(false),
-            _ => false,
-        };
-        out.push((start..i, token));
+        let token = (start..i, token);
+        (after_condition, after_for_of) = advance_context(js, &token, &out, &mut delimiters);
+        out.push(token);
     }
     (out, comments)
 }
 
+/// Advance only the delimiter/for-header context after a token has been classified.
+/// Returns whether it closes a statement's condition or is the for-of separator.
+fn advance_context(js: &str, token: &Token, tokens: &[Token], delimiters: &mut Vec<(char, Delimiter)>) -> (bool, bool) {
+    let mut after_for_of = false;
+    if let Some((_, Delimiter::For { left })) = delimiters.last_mut() {
+        if matches!(token.1, Js::Ident) && js.get(token.0.clone()) == Some("of") && *left && for_target_ends(js, tokens) {
+            *left = false;
+            after_for_of = true;
+        } else if matches!(token.1, Js::Punct(';' | '='))
+            || (matches!(token.1, Js::Ident) && js.get(token.0.clone()) == Some("in") && !matches!(tokens.last(), Some((_, Js::Punct('.')))))
+        {
+            *left = false;
+        }
+    }
+    let mut after_condition = false;
+    match token.1 {
+        Js::Punct('(') => delimiters.push((')', opens_condition(js, tokens))),
+        Js::Punct('[') => delimiters.push((']', Delimiter::Group)),
+        Js::Punct('{') => delimiters.push(('}', Delimiter::Group)),
+        Js::Punct(close @ (')' | ']' | '}')) if delimiters.last().is_some_and(|(end, _)| *end == close) => {
+            after_condition = matches!(delimiters.pop(), Some((_, Delimiter::Condition | Delimiter::For { .. })));
+        }
+        _ => {}
+    }
+    (after_condition, after_for_of)
+}
+
 /// Whether a `/` after `tokens` starts a regular expression: after an operator, an opening
 /// bracket, a keyword such as `return` or the condition of `if`, `while`, `for` or `with`, not
 /// after a value. `after_condition` says the last token is the `)` that ends such a condition.
-fn regex_may_follow(js: &str, tokens: &[Token], after_condition: bool) -> bool {
+fn regex_may_follow(js: &str, tokens: &[Token], after_condition: bool, after_for_of: bool) -> bool {
     match tokens.last() {
         None => true,
-        Some((range, Js::Ident)) => js.get(range.clone()).is_some_and(|w| BEFORE_REGEX.contains(&w)),
+        Some((range, Js::Ident)) => {
+            !matches!(tokens.get(tokens.len().wrapping_sub(2)), Some((_, Js::Punct('.'))))
+                && js.get(range.clone()).is_some_and(|w| BEFORE_REGEX.contains(&w) || (w == "of" && after_for_of))
+        }
         Some((_, Js::Punct(')'))) => after_condition,
         Some((_, Js::Punct(c))) => !matches!(c, ']' | '}'),
         Some((_, Js::Str(_) | Js::Other)) => false,
     }
 }
 
-/// Whether a `(` after `tokens` opens the condition of `if`, `while`, `for` or `with`, and not
+/// Whether a `(` after `tokens` opens the condition of `if`, `while`, `for` (including
+/// `for await`) or `with`, and not
 /// the arguments of a method that has one of those names (`o.if(x)`).
-fn opens_condition(js: &str, tokens: &[Token]) -> bool {
+fn opens_condition(js: &str, tokens: &[Token]) -> Delimiter {
     let mut back = tokens.iter().rev();
-    let Some((range, Js::Ident)) = back.next() else { return false };
-    js.get(range.clone()).is_some_and(|w| BEFORE_CONDITION.contains(&w)) && !matches!(back.next(), Some((_, Js::Punct('.'))))
+    let Some((range, Js::Ident)) = back.next() else { return Delimiter::Group };
+    let mut keyword = js.get(range.clone());
+    if keyword == Some("await") {
+        let Some((range, Js::Ident)) = back.next() else { return Delimiter::Group };
+        keyword = js.get(range.clone());
+        if keyword != Some("for") {
+            return Delimiter::Group;
+        }
+    }
+    if matches!(back.next(), Some((_, Js::Punct('.')))) {
+        return Delimiter::Group;
+    }
+    match keyword {
+        Some("for") => Delimiter::For { left: true },
+        Some(w) if BEFORE_CONDITION.contains(&w) => Delimiter::Condition,
+        _ => Delimiter::Group,
+    }
+}
+
+/// A binding/assignment target before the for-of separator, not a declaration keyword,
+/// expression-opening operator, or the start of the header itself.
+fn for_target_ends(js: &str, tokens: &[Token]) -> bool {
+    match tokens.last() {
+        Some((range, Js::Ident)) => !matches!(js.get(range.clone()), Some("var" | "let" | "const")),
+        Some((_, Js::Punct(']' | '}' | ')'))) => true,
+        _ => false,
+    }
 }
 
 /// Where a Calculate script keeps its simplified field notation: between `BVCALC` and the
@@ -455,10 +536,12 @@ fn splice(src: &str, edits: impl IntoIterator<Item = (Range<usize>, String)>) ->
 }
 
 /// Simplified field notation as the JavaScript Acrobat writes after its `BVCALC` comment:
-/// each field name becomes `AFMakeNumber(this.getField("name").value)`, the rest stays.
+/// Each field name becomes `AFMakeNumber(this.getField("name").value)`; adjacent signs
+/// are separated so binary plus/minus followed by a unary sign cannot become an update.
 pub fn notation_js(expr: &str) -> String {
     let names = notation_tokens(expr).into_iter().filter_map(|(range, t)| match t {
         Notation::Name(name) => Some((range, format!("AFMakeNumber(this.getField({}).value)", js_str(&name)))),
+        Notation::Op(sign @ ('+' | '-')) if expr.get(range.end..).is_some_and(|rest| rest.starts_with(sign)) => Some((range, format!("{sign} "))),
         _ => None,
     });
     splice(expr, names)
@@ -507,6 +590,10 @@ pub(super) fn eval_notation(src: &str, value_of: &dyn Fn(&str) -> f64) -> Option
                 *i += 1;
                 Some(*n)
             }
+            T::Op('+') => {
+                *i += 1;
+                factor(t, i, d + 1)
+            }
             T::Op('-') => {
                 *i += 1;
                 factor(t, i, d + 1).map(|v| -v)
@@ -558,3 +645,33 @@ pub fn calculate(c: &Calculate, values: &dyn Fn(&str) -> Vec<String>) -> Option<
         }
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn regex_scan_does_not_cross_line_break_after_backslash_or_split_utf8() {
+        let js = "x = /a\\\nthis.getField(\"price\").value / 2;";
+        assert_eq!(calculation_reads(js), vec!["price".to_owned()]);
+
+        let js_utf8 = "var r = /\\é/; event.value = this.getField(\"tax\").value;";
+        assert_eq!(calculation_reads(js_utf8), vec!["tax".to_owned()]);
+
+        let trailing_backslash = "event.value = this.getField(\"subtotal\").value + /unterminated\\";
+        assert_eq!(calculation_reads(trailing_backslash), vec!["subtotal".to_owned()]);
+        let template_trailing = "event.value = this.getField(\"shipping\").value + `unterminated\\";
+        assert_eq!(calculation_reads(template_trailing), vec!["shipping".to_owned()]);
+    }
+
+    #[test]
+    fn eval_notation_supports_unary_plus() {
+        let c = Calculate::Notation("+a + (+b)".to_owned());
+        let out = calculate(&c, &|name| match name {
+            "a" => vec!["3".to_owned()],
+            "b" => vec!["4".to_owned()],
+            _ => Vec::new(),
+        });
+        assert_eq!(out.as_deref(), Some("7"));
+    }
+}
diff --git a/crates/forms/src/af/script.rs b/crates/forms/src/af/script.rs
index f15714c411..8212da5bf2 100644
--- a/crates/forms/src/af/script.rs
+++ b/crates/forms/src/af/script.rs
@@ -17,7 +17,7 @@ impl Arg {
         match self {
             Arg::Num(n) => Some(*n),
             Arg::Bool(b) => Some(f64::from(u8::from(*b))),
-            Arg::Str(s) => s.trim().parse().ok(),
+            Arg::Str(s) => s.trim().parse::<f64>().ok().filter(|n| n.is_finite()),
             Arg::List(_) => None,
         }
     }
@@ -99,17 +99,36 @@ impl Parser<'_> {
                             let mut encoded = [0u8; 4];
                             out.extend_from_slice(ch.encode_utf8(&mut encoded).as_bytes());
                         }
+                        b'u' if self.s.get(self.i) == Some(&b'{') => {
+                            self.i += 1;
+                            let start = self.i;
+                            let mut code = 0u32;
+                            while let Some(&digit) = self.s.get(self.i).filter(|&&b| b != b'}') {
+                                code = code.checked_mul(16)?.checked_add(char::from(digit).to_digit(16)?)?;
+                                if code > 0x10FFFF {
+                                    return None;
+                                }
+                                self.i += 1;
+                            }
+                            if self.i == start || self.s.get(self.i) != Some(&b'}') {
+                                return None;
+                            }
+                            self.i += 1;
+                            // Match the existing handling of unpaired UTF-16 surrogates.
+                            let ch = char::from_u32(code).unwrap_or('\u{FFFD}');
+                            let mut encoded = [0u8; 4];
+                            out.extend_from_slice(ch.encode_utf8(&mut encoded).as_bytes());
+                        }
                         b'u' => {
                             let code = hex4(self.s.get(self.i..self.i.checked_add(4)?)?)?;
                             self.i += 4;
-                            let code = if (0xD800..=0xDBFF).contains(&code) && self.s.get(self.i..self.i.checked_add(6)?)?.starts_with(b"\\u") {
-                                let low = hex4(self.s.get(self.i.checked_add(2)?..self.i.checked_add(6)?)?)?;
-                                if (0xDC00..=0xDFFF).contains(&low) {
-                                    self.i += 6;
-                                    0x10000 + ((u32::from(code) - 0xD800) << 10) + (u32::from(low) - 0xDC00)
-                                } else {
-                                    u32::from(code)
-                                }
+                            let code = if (0xD800..=0xDBFF).contains(&code)
+                                && let Some(pair) = self.i.checked_add(6).and_then(|end| self.s.get(self.i..end))
+                                && pair.starts_with(b"\\u")
+                                && let Some(low) = hex4(&pair[2..6]).filter(|low| (0xDC00..=0xDFFF).contains(low))
+                            {
+                                self.i += 6;
+                                0x10000 + ((u32::from(code) - 0xD800) << 10) + (u32::from(low) - 0xDC00)
                             } else {
                                 u32::from(code)
                             };
@@ -158,7 +177,7 @@ impl Parser<'_> {
                 while self.i < self.s.len() && (self.s[self.i].is_ascii_digit() || matches!(self.s[self.i], b'.' | b'-' | b'+' | b'e' | b'E')) {
                     self.i += 1;
                 }
-                std::str::from_utf8(&self.s[start..self.i]).ok()?.parse().ok().map(Arg::Num)
+                std::str::from_utf8(&self.s[start..self.i]).ok()?.parse::<f64>().ok().filter(|n| n.is_finite()).map(Arg::Num)
             }
         }
     }
@@ -196,15 +215,30 @@ impl Parser<'_> {
     }
 }
 
-/// The first call to `name(` in `js` and its arguments.
+/// The first genuine call to `name(` in `js` and its arguments.
+/// An unsupported first call returns `None`, preserving the custom-script fallback; later calls
+/// must not substitute a different native rule. Comments, strings and unrelated identifiers are skipped.
 pub(super) fn call(js: &str, name: &str) -> Option<Vec<Arg>> {
-    let at = js.find(&format!("{name}("))?;
-    // Not part of a longer identifier (AFDate_Format vs AFDate_FormatEx).
-    if js[..at].chars().last().is_some_and(|c| c.is_alphanumeric() || c == '_') {
-        return None;
+    let (tokens, _) = js_tokens(js);
+    for (k, (range, tok)) in tokens.iter().enumerate() {
+        if *tok != super::calc::Js::Ident {
+            continue;
+        }
+        if k > 0 && matches!(tokens.get(k - 1), Some((_, super::calc::Js::Punct('.')))) {
+            continue;
+        }
+        let Some(target_end) = range.start.checked_add(name.len()) else { continue };
+        if js.get(range.start..target_end) != Some(name) {
+            continue;
+        }
+        let Some(end_k) = (k..tokens.len()).take_while(|&m| tokens[m].0.end <= target_end).find(|&m| tokens[m].0.end == target_end) else {
+            continue;
+        };
+        let Some((open, super::calc::Js::Punct('('))) = tokens.get(end_k + 1) else { continue };
+        let mut p = Parser { s: js.as_bytes(), i: open.end, depth: 0 };
+        return p.list(b')');
     }
-    let mut p = Parser { s: js.as_bytes(), i: at + name.len() + 1, depth: 0 };
-    p.list(b')')
+    None
 }
 
 pub fn parse_format(js: &str) -> Option<Format> {
@@ -246,7 +280,8 @@ pub fn parse_validate(js: &str) -> Option<Validate> {
     let args = call(js, "AFRange_Validate")?;
     let flag = |i: usize| args.get(i).is_some_and(Arg::truthy);
     let num = |i: usize| args.get(i).and_then(Arg::num);
-    Some(Validate::Range { min: if flag(0) { num(1) } else { None }, max: if flag(2) { num(3) } else { None } })
+    // An enabled but unparseable bound is unsupported, not an absent bound.
+    Some(Validate::Range { min: if flag(0) { Some(num(1)?) } else { None }, max: if flag(2) { Some(num(3)?) } else { None } })
 }
 
 pub fn parse_calculate(js: &str) -> Option<Calculate> {
@@ -361,3 +396,89 @@ pub fn calculate_js(c: &Calculate) -> Option<String> {
         Calculate::Notation(expr) => Some(format!("/** BVCALC {expr} EVCALC **/ event.value = {};", notation_js(expr))),
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn unsupported_first_validation_call_does_not_select_a_later_rule() {
+        let js = "if (event.value < 50) AFRange_Validate(true, 10 + 5, false, 0); else AFRange_Validate(false, 0, true, 100);";
+        assert_eq!(parse_validate(js), None);
+        assert_eq!(
+            parse_validate("AFRange_Validate(true, 15, false, 0); AFRange_Validate(false, 0, true, 100);"),
+            Some(Validate::Range { min: Some(15.0), max: None })
+        );
+    }
+
+    #[test]
+    fn validation_call_still_skips_non_calls_before_literal_arguments() {
+        let js = r#"// AFRange_Validate(true, 10 + 5, false, 0)
+            "AFRange_Validate(true, 10 + 5, false, 0)";
+            my_AFRange_Validate(true, 10 + 5, false, 0);
+            other.AFRange_Validate(true, 10 + 5, false, 0);
+            AFRange_Validate(false, 0, true, 100);"#;
+        assert_eq!(parse_validate(js), Some(Validate::Range { min: None, max: Some(100.0) }));
+    }
+
+    #[test]
+    fn unpaired_high_surrogate_at_end_of_string_does_not_abort_parsing() {
+        let js = "AFDate_FormatEx(\"\\uD800\")";
+        assert_eq!(parse_format(js), Some(Format::Date("\u{FFFD}".to_owned())));
+    }
+
+    #[test]
+    fn call_skips_commented_or_prefixed_identifiers_and_rejects_infinite_numbers() {
+        let js = "// AFPercent_Format(0, 0);\nmy_AFPercent_Format(0, 0); $AFPercent_Format(0, 0); AFPercent_Format (2, 1);";
+        assert_eq!(parse_format(js), Some(Format::Percent { decimals: 2, sep: 1 }));
+
+        assert_eq!(parse_validate("AFRange_Validate(true, 1e500, false, 0);"), None);
+    }
+    #[test]
+    fn review_enabled_nonfinite_bound_is_unsupported() {
+        for script in [r#"AFRange_Validate(true, "1e500", false, 0)"#, r#"AFRange_Validate(false, 0, true, "-1e500")"#] {
+            assert_eq!(parse_validate(script), None);
+        }
+        assert_eq!(parse_validate(r#"AFRange_Validate(false, "1e500", false, "NaN")"#), Some(Validate::Range { min: None, max: None }));
+    }
+
+    #[test]
+    fn review_format_after_postfix_division() {
+        for op in ["++", "--"] {
+            let js = format!("var y = x{op} / 2; AFPercent_Format(2, 1); var z = 1 / 2;");
+            assert_eq!(parse_format(&js), Some(Format::Percent { decimals: 2, sep: 1 }));
+            let commented = format!("var y = x/* comment */{op} / 2; AFPercent_Format(2, 1); var z = 1 / 2;");
+            assert_eq!(parse_format(&commented), Some(Format::Percent { decimals: 2, sep: 1 }));
+        }
+        assert_eq!(parse_format("var of = 8; of / 2; AFPercent_Format(2, 1); var z = 1 / 2;"), Some(Format::Percent { decimals: 2, sep: 1 }));
+        assert_eq!(
+            parse_format("for (var x of /AFPercent_Format(0, 0)/g) {} AFPercent_Format(2, 1);"),
+            Some(Format::Percent { decimals: 2, sep: 1 })
+        );
+        // A newline makes ++ a prefix operator; the following regex must remain opaque.
+        for js in ["x\n++/AFPercent_Format(2, 1)/.lastIndex;", "x/*\n*/++/AFPercent_Format(2, 1)/.lastIndex;"] {
+            assert_eq!(parse_format(js), None);
+        }
+    }
+
+    #[test]
+    fn review_format_after_brace_unicode() {
+        assert_eq!(parse_format(r#"var s = "\u{1F600}"; AFPercent_Format(2, 1);"#), Some(Format::Percent { decimals: 2, sep: 1 }));
+        assert_eq!(parse_format(r#"AFDate_FormatEx("\u{1F600}")"#), Some(Format::Date("😀".to_owned())));
+        assert_eq!(parse_format(r#"AFDate_FormatEx("\u{00000041}\u0042\uD83D\uDE00")"#), Some(Format::Date("AB😀".to_owned())));
+        for escape in ["\\u{}", "\\u{110000}", "\\u{xyz}", "\\u{41"] {
+            assert_eq!(parse_format(&format!("AFDate_FormatEx(\"{escape}\")")), None);
+        }
+    }
+
+    #[test]
+    fn review_notation_separates_adjacent_operators() {
+        let field = |name| format!("AFMakeNumber(this.getField(\"{name}\").value)");
+        for (expr, operators) in [("a++b", "+ +"), ("a--b", "- -"), ("a+++b", "+ + +")] {
+            let js = calculate_js(&Calculate::Notation(expr.to_owned())).unwrap();
+            let executable = js.split("event.value = ").nth(1).unwrap();
+            assert_eq!(executable, format!("{}{operators}{};", field("a"), field("b")));
+            assert_eq!(super::super::calc::calculate(&Calculate::Notation(expr.to_owned()), &|_| vec!["2".to_owned()]), Some("4".to_owned()));
+        }
+    }
+}
diff --git a/crates/forms/src/af/tests.rs b/crates/forms/src/af/tests.rs
index 1e546db75a..3c6dab1bef 100644
--- a/crates/forms/src/af/tests.rs
+++ b/crates/forms/src/af/tests.rs
@@ -444,3 +444,45 @@ fn validation_and_calculation() {
     assert_eq!(calculate(&Calculate::Notation("(a + b) * 2 - Unit\\ Price / 4".into()), &vals), Some("10".into()));
     assert_eq!(calculate(&Calculate::Notation("a +".into()), &vals), None);
 }
+
+/// Async for-of headers have the same regex-literal contexts as ordinary for-of headers.
+#[test]
+fn for_await_regex_literals_do_not_become_format_calls() {
+    for header in ["for await", "for /* gap */ await"] {
+        let js = format!("async function f() {{ {header} (const x of /AFPercent_Format(0, 0)/g) {{}} }} AFPercent_Format(2, 1);");
+        assert_eq!(parse_format(&js), Some(Format::Percent { decimals: 2, sep: 1 }));
+        let body = format!("async function f() {{ {header} (const x of xs) /AFPercent_Format(0, 0)/.test(x); }} AFPercent_Format(2, 1);");
+        assert_eq!(parse_format(&body), Some(Format::Percent { decimals: 2, sep: 1 }));
+    }
+    assert_eq!(parse_format("obj.await(x) / 2; AFPercent_Format(2, 1); var z = 1 / 2;"), Some(Format::Percent { decimals: 2, sep: 1 }));
+}
+
+#[test]
+fn identifier_of_in_conditions_keeps_division_and_real_format_calls() {
+    for header in [
+        "if (of / 2)",
+        "while (of / 2)",
+        "with (of / 2)",
+        "for (of / 2; ; )",
+        "for (var x = of / 2; ; )",
+        "for (var x = 0; of / 2; )",
+        "for (x of of / 2)",
+        "for (const x of of / 2)",
+        "for (x in of / 2)",
+        "for (var of / 2; ; )",
+        "for (obj.of / 2; ; )",
+    ] {
+        let js = format!("{header} AFPercent_Format(2, 1); var z = 1 / 2;");
+        assert_eq!(parse_format(&js), Some(Format::Percent { decimals: 2, sep: 1 }), "{header}");
+    }
+}
+
+#[test]
+fn destructured_for_of_targets_keep_regex_iterables_opaque() {
+    for header in ["for", "for await"] {
+        for target in ["const [x]", "const {x}", "(x)", "const {x = of / 2}", "obj.in", "obj.of", "const of"] {
+            let js = format!("async function f() {{ {header} ({target} of /AFPercent_Format(0, 0)/g) {{}} }} AFPercent_Format(2, 1);");
+            assert_eq!(parse_format(&js), Some(Format::Percent { decimals: 2, sep: 1 }), "{header} {target}");
+        }
+    }
+}
diff --git a/crates/forms/src/author/join.rs b/crates/forms/src/author/join.rs
index e9fedbd655..b8c2520dd6 100644
--- a/crates/forms/src/author/join.rs
+++ b/crates/forms/src/author/join.rs
@@ -5,16 +5,17 @@
 use std::collections::{HashMap, HashSet};
 
 use super::lifecycle::{drop_from_calculation_order, split_merged, split_triggers};
-use super::tree::{detach, list_of};
+use super::tree::{ancestor_sets, detach, list_of};
 use super::{Dict, Document, Field, FormError, ObjRef, Object, invalid};
 
 /// The keys a field that is also its own widget sheds when it becomes only a widget. Its `/AA`
 /// keeps only the widget's own triggers.
 const FIELD_ONLY_KEYS: [&[u8]; 15] = [b"T", b"FT", b"Kids", b"Ff", b"V", b"DV", b"Opt", b"TU", b"TM", b"MaxLen", b"Q", b"DS", b"RV", b"TI", b"I"];
 
-/// Whether `field` holds `/Opt`, which its buttons' export values index (ISO 32000-2 §12.7.5.2).
+/// Whether `field` holds or inherits `/Opt`, which its buttons' export values index (ISO 32000-2 §12.7.5.2).
 fn has_opt(doc: &Document, field: ObjRef) -> bool {
-    doc.get(field).as_dict().is_some_and(|d| d.contains(b"Opt"))
+    doc.get(field).as_dict().and_then(|d| d.get(b"Opt")).is_some_and(|v| !matches!(*doc.resolve(v), Object::Null))
+        || ancestor_sets(doc, field, b"Opt")
 }
 
 /// Refuse what [`join_radio_group`] can't do, before anything is written.
@@ -127,3 +128,26 @@ fn rename_state(doc: &Document, d: &mut Dict, old: &str, new: &str) -> bool {
     d.set(b"AP".to_vec(), Object::Dict(ap));
     true
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn has_opt_ignores_null_and_detects_inherited_opt() {
+        let mut doc = Document::new_empty();
+        let mut parent = Dict::new();
+        parent.set(b"Opt".to_vec(), Object::Array(vec![]));
+        let parent_ref = doc.add(Object::Dict(parent));
+
+        let mut f_null = Dict::new();
+        f_null.set(b"Opt".to_vec(), Object::Null);
+        let f_null_ref = doc.add(Object::Dict(f_null));
+        assert!(!has_opt(&doc, f_null_ref));
+
+        let mut f_inherited = Dict::new();
+        f_inherited.set(b"Parent".to_vec(), Object::Ref(parent_ref));
+        let f_inherited_ref = doc.add(Object::Dict(f_inherited));
+        assert!(has_opt(&doc, f_inherited_ref));
+    }
+}
diff --git a/crates/forms/src/author/tree.rs b/crates/forms/src/author/tree.rs
index ce4ee687bb..55b84fa390 100644
--- a/crates/forms/src/author/tree.rs
+++ b/crates/forms/src/author/tree.rs
@@ -112,6 +112,11 @@ pub(crate) fn form_fonts_as_objects(doc: &mut Document, all: &[crate::Field]) ->
     Ok(())
 }
 
+/// Whether `d` has a non-null entry `key` (a `null` entry is absent per ISO 32000-2 §7.3.9).
+fn dict_has(doc: &Document, d: &Dict, key: &[u8]) -> bool {
+    d.get(key).is_some_and(|v| !matches!(*doc.resolve(v), Object::Null))
+}
+
 /// Whether the field `r`, or the nearest ancestor that has one, holds a `/V` (the entry is
 /// inheritable, ISO 32000-2 §12.7.4). The `/Parent` chain is followed at most 64 deep, as deep
 /// as the field walk goes, so a cyclic chain ends.
@@ -120,7 +125,7 @@ fn holds_value(doc: &Document, r: ObjRef) -> bool {
     for _ in 0..=64 {
         let obj = doc.get(at);
         let Some(d) = obj.as_dict() else { return false };
-        if d.contains(b"V") {
+        if dict_has(doc, d, b"V") {
             return true;
         }
         match d.reference(b"Parent") {
@@ -160,8 +165,8 @@ fn add_to_fields(doc: &mut Document, af: ObjRef, field: ObjRef) -> Result<(), Fo
 /// The most parts a dotted field name may have ("a.b.c" has three).
 const MAX_NAME_PARTS: usize = 32;
 
-/// The field attributes a field inherits from its parents (ISO 32000-2 §12.7.4.1).
-const INHERITED_KEYS: [&[u8]; 7] = [b"FT", b"Ff", b"V", b"DV", b"DA", b"Q", b"MaxLen"];
+/// The field attributes a field inherits from its parents (ISO 32000-2 §12.7.4.1, §12.7.5.2).
+const INHERITED_KEYS: [&[u8]; 8] = [b"FT", b"Ff", b"V", b"DV", b"DA", b"Q", b"MaxLen", b"Opt"];
 
 /// The parts of a full field name: `a.b` is the field `b` under the parent field `a`, since a
 /// field's own (partial) name can't contain a period (ISO 32000-2 §12.7.4.2) (#2696).
@@ -234,7 +239,7 @@ pub(super) fn check_place(doc: &Document, af: ObjRef, field: ObjRef, parts: &[&s
             break;
         };
         // A value, reset value or length limit held by a parent would pass to this field.
-        let held = doc.get(r).as_dict().is_some_and(|d| PASSED_VALUES.iter().any(|k| d.contains(k) && !owned.contains(k)));
+        let held = doc.get(r).as_dict().is_some_and(|d| PASSED_VALUES.iter().any(|k| dict_has(doc, d, k) && !dict_has(doc, &owned, k)));
         if held {
             return invalid(format!("{part:?} holds a value for the fields under it, so {:?} can't be put there", parts.join(".")));
         }
@@ -259,7 +264,7 @@ pub(super) fn attach(doc: &mut Document, af: ObjRef, field: ObjRef, parts: &[&st
     for part in parents {
         let next = match child_named(doc, af, parent, part) {
             Some(r) => {
-                inherits |= doc.get(r).as_dict().is_some_and(|d| d.contains(b"Ff") || d.contains(b"Q"));
+                inherits |= doc.get(r).as_dict().is_some_and(|d| dict_has(doc, d, b"Ff") || dict_has(doc, d, b"Q"));
                 r
             }
             None => {
@@ -308,12 +313,20 @@ pub(super) fn inherited(doc: &Document, field: ObjRef) -> Dict {
         }
         let Some(d) = doc.get(p).as_dict().cloned() else { break };
         for k in INHERITED_KEYS {
-            if let Some(v) = d.get(k).filter(|_| !own.contains(k) && !add.contains(k)) {
+            if let Some(v) = d.get(k).filter(|_| dict_has(doc, &d, k) && !dict_has(doc, &own, k) && !add.contains(k)) {
                 add.set(k.to_vec(), v.clone());
             }
         }
         parent = d.reference(b"Parent");
     }
+    // /Opt is inheritable for check boxes and radio buttons (Table 230), not choice
+    // fields (Table 234). Classify by effective /FT and /Ff before materializing it.
+    let effective = |key: &[u8]| if dict_has(doc, &own, key) { own.get(key) } else { add.get(key) };
+    let button = effective(b"FT").is_some_and(|v| doc.resolve(v).as_name() == Some(b"Btn"));
+    let flags = effective(b"Ff").and_then(|v| doc.resolve(v).as_int()).and_then(|v| u32::try_from(v).ok()).unwrap_or(0);
+    if !button || flags & crate::flags::PUSH_BUTTON != 0 {
+        add.remove(b"Opt");
+    }
     add
 }
 
@@ -327,7 +340,7 @@ pub(crate) fn ancestor_sets(doc: &Document, field: ObjRef, key: &[u8]) -> bool {
             return false;
         }
         let Some(d) = doc.get(p).as_dict().cloned() else { return false };
-        if d.contains(key) {
+        if dict_has(doc, &d, key) {
             return true;
         }
         parent = d.reference(b"Parent");
@@ -396,3 +409,162 @@ pub(super) fn top_names(doc: &Document) -> Vec<String> {
     let list = af.get(b"Fields").map(|o| doc.resolve(o)).and_then(|o| o.as_array().cloned()).unwrap_or_default();
     list.iter().filter_map(|o| doc.resolve(o).as_dict().and_then(|d| d.get(b"T").cloned())).filter_map(|t| crate::text_of(&doc.resolve(&t))).collect()
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    /// /Opt is inheritable only for check boxes and radio buttons, using effective FT/Ff.
+    #[test]
+    fn inherited_options_are_limited_to_checkboxes_and_radios() {
+        for (ft, flags, expected) in
+            [("Btn", 0, true), ("Btn", crate::flags::RADIO, true), ("Btn", crate::flags::PUSH_BUTTON, false), ("Ch", 0, false), ("Tx", 0, false)]
+        {
+            for own_type in [false, true] {
+                let mut doc = Document::new_empty();
+                let mut parent = Dict::new();
+                parent.set(b"FT".to_vec(), Object::name(ft));
+                parent.set(b"Ff".to_vec(), Object::Int(i64::from(flags)));
+                parent.set(b"Opt".to_vec(), Object::Array(vec![Object::String(PdfString::text("export"))]));
+                parent.set(b"DA".to_vec(), PdfString::text("/Helv 10 Tf 0 g"));
+                let p = doc.add(parent);
+                let mut child = Dict::new();
+                child.set(b"Parent".to_vec(), Object::Ref(p));
+                if own_type {
+                    child.set(b"FT".to_vec(), Object::name(ft));
+                    child.set(b"Ff".to_vec(), Object::Int(i64::from(flags)));
+                }
+                let c = doc.add(child);
+                let inherited = inherited(&doc, c);
+                assert_eq!(inherited.contains(b"Opt"), expected, "{ft}, flags {flags}, own {own_type}");
+                assert!(inherited.contains(b"DA"));
+            }
+        }
+    }
+
+    fn one_page() -> Document {
+        let mut doc = Document::new_empty();
+        let pages = doc.get(doc.root().unwrap()).as_dict().unwrap().reference(b"Pages").unwrap();
+        let mut page = Dict::new();
+        page.set(b"Type".to_vec(), Object::name("Page"));
+        page.set(b"Parent".to_vec(), Object::Ref(pages));
+        page.set(b"MediaBox".to_vec(), Object::Array(vec![0.into(), 0.into(), 600.into(), 800.into()]));
+        let page = doc.add(page);
+        doc.update_dict(pages, |d| {
+            d.set(b"Kids".to_vec(), Object::Array(vec![Object::Ref(page)]));
+            d.set(b"Count".to_vec(), Object::Int(1));
+        })
+        .unwrap();
+        doc
+    }
+
+    fn reopen(doc: &Document) -> Document {
+        let bytes = pdfcraft_cos::write_incremental(doc, &pdfcraft_cos::SaveOptions::default()).unwrap();
+        hayro_syntax::Pdf::new(bytes.clone()).unwrap();
+        Document::open(std::sync::Arc::new(bytes)).unwrap()
+    }
+
+    /// Moving a choice field must not turn its ancestor's unrelated /Opt into local choices.
+    #[test]
+    fn moving_choice_fields_does_not_copy_ancestor_options() {
+        for combo in [false, true] {
+            for own_options in [false, true] {
+                let mut doc = one_page();
+                let options = if own_options { vec!["local".into()] } else { Vec::new() };
+                let kind = if combo { crate::NewField::Combo { options, editable: false } } else { crate::NewField::List { options, multi: false } };
+                crate::add_field(&mut doc, 0, [50.0, 700.0, 250.0, 720.0], &kind, Some("old.pick")).unwrap();
+                let f = crate::fields(&doc).into_iter().find(|f| f.name == "old.pick").unwrap();
+                let parent = doc.get(f.obj).as_dict().unwrap().reference(b"Parent").unwrap();
+                if !own_options {
+                    doc.update_dict(f.obj, |d| {
+                        d.remove(b"Opt");
+                    })
+                    .unwrap();
+                }
+                doc.update_dict(parent, |d| d.set(b"Opt".to_vec(), Object::Array(vec![Object::String(PdfString::text("borrowed"))]))).unwrap();
+                let before = crate::fields(&doc).into_iter().find(|f| f.name == "old.pick").unwrap().options;
+                crate::set_props(&mut doc, "old.pick", &crate::FieldProps { name: Some("new.pick".into()), ..Default::default() }).unwrap();
+                let after = crate::fields(&doc).into_iter().find(|f| f.name == "new.pick").unwrap();
+                assert_eq!(after.options, before);
+                assert_eq!(doc.get(after.obj).as_dict().unwrap().contains(b"Opt"), own_options);
+                let reopened = reopen(&doc);
+                let after = crate::fields(&reopened).into_iter().find(|f| f.name == "new.pick").unwrap();
+                assert_eq!(after.options, before);
+                assert_eq!(reopened.get(after.obj).as_dict().unwrap().contains(b"Opt"), own_options);
+            }
+        }
+    }
+
+    #[test]
+    fn moving_buttons_preserves_inherited_export_mapping() {
+        for kind in [crate::NewField::CheckBox, crate::NewField::Radio { group: None, export: "0".into() }] {
+            let mut doc = one_page();
+            crate::add_field(&mut doc, 0, [50.0, 700.0, 70.0, 720.0], &kind, Some("old.button")).unwrap();
+            let field = crate::fields(&doc).into_iter().find(|f| f.name == "old.button").unwrap();
+            let state = field.widgets.first().unwrap().on_state.clone().unwrap();
+            let parent = doc.get(field.obj).as_dict().unwrap().reference(b"Parent").unwrap();
+            let opt = Object::Array(vec![Object::String(PdfString::text("exported"))]);
+            doc.update_dict(parent, |d| d.set(b"Opt".to_vec(), opt.clone())).unwrap();
+            doc.update_dict(field.obj, |d| {
+                d.remove(b"Opt");
+            })
+            .unwrap();
+            crate::set_props(&mut doc, "old.button", &crate::FieldProps { name: Some("new.button".into()), ..Default::default() }).unwrap();
+            for doc in [&doc, &reopen(&doc)] {
+                let after = crate::fields(doc).into_iter().find(|f| f.name == "new.button").unwrap();
+                assert_eq!(doc.get(after.obj).as_dict().unwrap().get(b"Opt"), Some(&opt));
+                assert_eq!(after.export_of(0), Some("exported"));
+                assert_eq!(after.state_for("exported"), Some(state.as_str()));
+            }
+        }
+    }
+
+    #[test]
+    fn null_entries_on_parents_and_unsigned_signatures_are_treated_as_absent() {
+        let mut doc = Document::new_empty();
+        let mut sig = Dict::new();
+        sig.set(b"FT".to_vec(), Object::name("Sig"));
+        sig.set(b"T".to_vec(), PdfString::text("sig"));
+        sig.set(b"V".to_vec(), Object::Null);
+        let sig_ref = doc.add(Object::Dict(sig));
+        assert!(!holds_value(&doc, sig_ref));
+
+        let mut grand = Dict::new();
+        grand.set(b"FT".to_vec(), Object::name("Tx"));
+        grand.set(b"MaxLen".to_vec(), Object::Int(10));
+        let grand_ref = doc.add(Object::Dict(grand));
+
+        let mut parent = Dict::new();
+        parent.set(b"Parent".to_vec(), Object::Ref(grand_ref));
+        parent.set(b"T".to_vec(), PdfString::text("group"));
+        parent.set(b"V".to_vec(), Object::Null);
+        parent.set(b"MaxLen".to_vec(), Object::Null);
+        let parent_ref = doc.add(Object::Dict(parent));
+
+        let mut child = Dict::new();
+        child.set(b"Parent".to_vec(), Object::Ref(parent_ref));
+        child.set(b"T".to_vec(), PdfString::text("item"));
+        let child_ref = doc.add(Object::Dict(child));
+
+        let inh = inherited(&doc, child_ref);
+        assert_eq!(inh.get(b"MaxLen"), Some(&Object::Int(10)));
+        assert!(!inh.contains(b"V"));
+        assert!(!ancestor_sets(&doc, child_ref, b"V"));
+        assert!(ancestor_sets(&doc, child_ref, b"MaxLen"));
+
+        // Button /Opt is inherited, text /Opt is not; null kids and /Parent cycles are handled.
+        let opt_val = Object::Array(vec![Object::String(PdfString::text("Choice1"))]);
+        doc.update_dict(grand_ref, |d| {
+            d.set(b"Opt".to_vec(), opt_val.clone());
+            d.set(b"Parent".to_vec(), Object::Ref(parent_ref));
+            d.set(b"Kids".to_vec(), Object::Array(vec![Object::Null, Object::Ref(parent_ref)]));
+        })
+        .unwrap();
+        assert!(!inherited(&doc, child_ref).contains(b"Opt"));
+        doc.update_dict(grand_ref, |d| d.set(b"FT".to_vec(), Object::name("Btn"))).unwrap();
+        let inh_cycle = inherited(&doc, child_ref);
+        assert_eq!(inh_cycle.get(b"Opt"), Some(&opt_val));
+        assert!(!holds_value(&doc, child_ref));
+        assert_eq!(child_named(&doc, grand_ref, Some(grand_ref), "group"), Some(parent_ref));
+    }
+}
diff --git a/crates/forms/src/tab_order.rs b/crates/forms/src/tab_order.rs
index 5b60e3927b..5c46293303 100644
--- a/crates/forms/src/tab_order.rs
+++ b/crates/forms/src/tab_order.rs
@@ -137,23 +137,34 @@ pub fn tab_orders(doc: &Document) -> Vec<TabOrder> {
 /// annotations keep their places.
 pub fn move_in_tab_order(doc: &mut Document, name: &str, earlier: bool) -> Result<(), FormError> {
     let all = fields(doc);
-    let f = all.iter().find(|f| f.name == name).ok_or_else(|| FormError::NoSuchField(name.into()))?;
-    let page = f.widgets.iter().filter_map(|w| w.page).min().ok_or_else(|| FormError::Invalid(format!("{name} is not on a page")))?;
+    if !all.iter().any(|f| f.name == name) {
+        return Err(FormError::NoSuchField(name.into()));
+    }
+    let (target_fi, page) = all
+        .iter()
+        .enumerate()
+        .filter(|(_, f)| f.name == name)
+        .find_map(|(fi, f)| Some((fi, f.widgets.iter().filter_map(|w| w.page).min()?)))
+        .ok_or_else(|| FormError::Invalid(format!("{name} is not on a page")))?;
     // The page's fields in their current tab order (a field counts once, at its first widget).
-    let mut order: Vec<(usize, &str)> =
-        all.iter().filter_map(|g| g.widgets.iter().filter(|w| w.page == Some(page)).map(|w| w.tab).min().map(|t| (t, g.name.as_str()))).collect();
+    let mut order: Vec<(usize, usize)> = all
+        .iter()
+        .enumerate()
+        .filter_map(|(fi, g)| g.widgets.iter().filter(|w| w.page == Some(page)).map(|w| w.tab).min().map(|t| (t, fi)))
+        .collect();
     order.sort();
-    let names: Vec<&str> = order.iter().map(|(_, n)| *n).collect();
-    let Some(i) = names.iter().position(|n| *n == name) else { return invalid(format!("{name} is not on a page")) };
-    let j = if earlier { i.checked_sub(1) } else { Some(i + 1).filter(|j| *j < names.len()) };
+    let Some(i) = order.iter().position(|&(_, fi)| fi == target_fi) else { return invalid(format!("{name} is not on a page")) };
+    let j = if earlier { i.checked_sub(1) } else { Some(i + 1).filter(|j| *j < order.len()) };
     let Some(j) = j else { return Ok(()) };
-    let mut names = names.into_iter().map(str::to_string).collect::<Vec<_>>();
-    names.swap(i, j);
-    // The widgets of this page in the new order.
+    order.swap(i, j);
+    // The widgets of this page in the new order, preserving each field's relative widget tab order.
     let mut widgets: Vec<ObjRef> = Vec::new();
-    for n in &names {
-        if let Some(g) = all.iter().find(|g| &g.name == n) {
-            widgets.extend(g.widgets.iter().filter(|w| w.page == Some(page)).map(|w| w.obj));
+    let mut queued = std::collections::HashSet::new();
+    for &(_, fi) in &order {
+        if let Some(g) = all.get(fi) {
+            let mut own: Vec<(usize, ObjRef)> = g.widgets.iter().filter(|w| w.page == Some(page)).map(|w| (w.tab, w.obj)).collect();
+            own.sort_by_key(|&(tab, _)| tab);
+            widgets.extend(own.into_iter().map(|(_, obj)| obj).filter(|obj| queued.insert(*obj)));
         }
     }
     let pr = *page_refs(doc).get(page).ok_or_else(|| FormError::Invalid("no such page".into()))?;
@@ -162,10 +173,11 @@ pub fn move_in_tab_order(doc: &mut Document, name: &str, earlier: bool) -> Resul
     let list = doc.resolve(&annots_obj).as_array().cloned().unwrap_or_default();
     let mut next = widgets.into_iter();
     let set: std::collections::HashSet<ObjRef> = all.iter().flat_map(|g| g.widgets.iter().filter(|w| w.page == Some(page)).map(|w| w.obj)).collect();
+    let mut seen_slots = std::collections::HashSet::new();
     let new_list: Vec<Object> = list
         .iter()
         .map(|o| match o.as_ref() {
-            Some(r) if set.contains(&r) => next.next().map(Object::Ref).unwrap_or_else(|| o.clone()),
+            Some(r) if set.contains(&r) && seen_slots.insert(r) => next.next().map(Object::Ref).unwrap_or_else(|| o.clone()),
             _ => o.clone(),
         })
         .collect();
@@ -178,3 +190,85 @@ pub fn move_in_tab_order(doc: &mut Document, name: &str, earlier: bool) -> Resul
     })?;
     Ok(())
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use pdfcraft_cos::{Dict, PdfString};
+
+    #[test]
+    fn move_in_tab_order_preserves_multi_widget_relative_tab_order() {
+        let mut doc = Document::new_empty();
+        let pages_ref = doc.add(Object::Null);
+        let page_ref = doc.add(Object::Null);
+
+        let mut w1 = Dict::new();
+        w1.set(b"Subtype".to_vec(), Object::name("Widget"));
+        w1.set(b"Rect".to_vec(), Object::Array(vec![Object::Int(200), Object::Int(700), Object::Int(220), Object::Int(720)]));
+        let w1_ref = doc.add(Object::Dict(w1));
+
+        let mut w2 = Dict::new();
+        w2.set(b"Subtype".to_vec(), Object::name("Widget"));
+        w2.set(b"Rect".to_vec(), Object::Array(vec![Object::Int(50), Object::Int(700), Object::Int(70), Object::Int(720)]));
+        let w2_ref = doc.add(Object::Dict(w2));
+
+        let mut radio = Dict::new();
+        radio.set(b"FT".to_vec(), Object::name("Btn"));
+        radio.set(b"Ff".to_vec(), Object::Int(1 << 15));
+        radio.set(b"T".to_vec(), PdfString::text("choice"));
+        // /Kids order is [w1 (right), w2 (left)], opposite to /R (Row) left-to-right order.
+        radio.set(b"Kids".to_vec(), Object::Array(vec![Object::Ref(w1_ref), Object::Ref(w2_ref)]));
+        let radio_ref = doc.add(Object::Dict(radio));
+        doc.update_dict(w1_ref, |d| d.set(b"Parent".to_vec(), Object::Ref(radio_ref))).unwrap();
+        doc.update_dict(w2_ref, |d| d.set(b"Parent".to_vec(), Object::Ref(radio_ref))).unwrap();
+
+        let mut text = Dict::new();
+        text.set(b"FT".to_vec(), Object::name("Tx"));
+        text.set(b"Subtype".to_vec(), Object::name("Widget"));
+        text.set(b"T".to_vec(), PdfString::text("note"));
+        text.set(b"Rect".to_vec(), Object::Array(vec![Object::Int(50), Object::Int(600), Object::Int(150), Object::Int(620)]));
+        let text_ref = doc.add(Object::Dict(text));
+
+        let mut page = Dict::new();
+        page.set(b"Type".to_vec(), Object::name("Page"));
+        page.set(b"Parent".to_vec(), Object::Ref(pages_ref));
+        page.set(b"Tabs".to_vec(), Object::name("R"));
+        page.set(b"Annots".to_vec(), Object::Array(vec![Object::Ref(w1_ref), Object::Ref(w2_ref), Object::Ref(text_ref)]));
+        doc.set(page_ref, Object::Dict(page));
+
+        let mut pages = Dict::new();
+        pages.set(b"Type".to_vec(), Object::name("Pages"));
+        pages.set(b"Kids".to_vec(), Object::Array(vec![Object::Ref(page_ref)]));
+        pages.set(b"Count".to_vec(), Object::Int(1));
+        doc.set(pages_ref, Object::Dict(pages));
+
+        let mut af = Dict::new();
+        af.set(b"Fields".to_vec(), Object::Array(vec![Object::Ref(radio_ref), Object::Ref(text_ref)]));
+        let af_ref = doc.add(Object::Dict(af));
+
+        let mut catalog = Dict::new();
+        catalog.set(b"Type".to_vec(), Object::name("Catalog"));
+        catalog.set(b"Pages".to_vec(), Object::Ref(pages_ref));
+        catalog.set(b"AcroForm".to_vec(), Object::Ref(af_ref));
+        let root_ref = doc.root().unwrap();
+        doc.set(root_ref, Object::Dict(catalog));
+
+        // Move "note" earlier (before "choice"): "choice"'s own buttons should stay in their
+        // /R tab order (w2 then w1), not revert to /Kids order (w1 then w2).
+        move_in_tab_order(&mut doc, "note", true).unwrap();
+        let annots = doc.get(page_ref).as_dict().and_then(|d| d.get(b"Annots")).and_then(Object::as_array).cloned().unwrap();
+        assert_eq!(annots, vec![Object::Ref(text_ref), Object::Ref(w2_ref), Object::Ref(w1_ref)]);
+
+        // Missing page and unplaced field return errors cleanly.
+        assert!(set_tab_order(&mut doc, &[99], TabOrder::Row).is_err());
+        let mut unplaced = Dict::new();
+        unplaced.set(b"FT".to_vec(), Object::name("Tx"));
+        unplaced.set(b"T".to_vec(), PdfString::text("orphan"));
+        let unplaced_ref = doc.add(Object::Dict(unplaced));
+        doc.update_dict(af_ref, |d| {
+            d.set(b"Fields".to_vec(), Object::Array(vec![Object::Ref(radio_ref), Object::Ref(text_ref), Object::Ref(unplaced_ref)]));
+        })
+        .unwrap();
+        assert!(move_in_tab_order(&mut doc, "orphan", true).is_err());
+    }
+}
diff --git a/crates/forms/src/tests.rs b/crates/forms/src/tests.rs
index a49d35b0f4..f00d1cad9a 100644
--- a/crates/forms/src/tests.rs
+++ b/crates/forms/src/tests.rs
@@ -1701,6 +1701,43 @@ fn a_script_that_spells_the_markers_in_a_string_runs_as_a_script() {
     assert_eq!(field(&fields(&doc), "total").value, ["ran"]);
 }
 
+/// An unsupported first AF call keeps the entire script and reaches the caller's interpreter.
+#[test]
+fn unsupported_first_validation_call_preserves_custom_script_dispatch() {
+    const JS: &str = "if (event.value < 50) AFRange_Validate(true, 10 + 5, false, 0); else AFRange_Validate(false, 0, true, 100);";
+    struct RejectingInterpreter {
+        calls: usize,
+    }
+    impl Scripts for RejectingInterpreter {
+        fn run(&mut self, event: FieldEvent, script: &str, target: &Field, value: &str, _fields: &[Field]) -> ScriptResult {
+            assert_eq!(event, FieldEvent::Validate);
+            assert_eq!(script, JS);
+            assert_eq!(target.name, "amount");
+            self.calls += 1;
+            ScriptResult { rc: false, value: value.into(), changes: Vec::new(), message: Some("custom validation ran".into()) }
+        }
+    }
+    let mut doc = one_page();
+    add_field(&mut doc, 0, [50.0, 700.0, 250.0, 720.0], &NewField::Text { multiline: false }, Some("amount")).unwrap();
+    set_value(&mut doc, "amount", &FieldValue::Text("20".into())).unwrap();
+    set_field_script(&mut doc, "amount", "validate", Some(JS)).unwrap();
+    let reopened = reopen(&doc);
+    for mut doc in [doc, reopened] {
+        let all = fields(&doc);
+        let actions = &field(&all, "amount").actions;
+        assert_eq!(actions.validate, af::Validate::None);
+        assert_eq!(actions.scripts.validate.as_deref(), Some(JS));
+        assert!(actions.unsupported.contains(&"validate"));
+        let mut scripts = RejectingInterpreter { calls: 0 };
+        assert_eq!(
+            set_value_with(&mut doc, "amount", &FieldValue::Text("10".into()), &mut scripts),
+            Err(FormError::Invalid("custom validation ran".into()))
+        );
+        assert_eq!(scripts.calls, 1);
+        assert_eq!(field(&fields(&doc), "amount").value, ["20"]);
+    }
+}
+
 /// Renaming a field renames it in the calculations that read it: a sum dropped it, notation
 /// read it as 0 and a script read a field that no longer existed.
 #[test]
diff --git a/parity/acrobat-features.toml b/parity/acrobat-features.toml
index 24b0e3e150..cc5231262b 100644
--- a/parity/acrobat-features.toml
+++ b/parity/acrobat-features.toml
@@ -4770,8 +4770,8 @@ milestone = "M6"
 status = "shipped"
 commands = ["form.field.properties"]
 tools = ["form_set_props", "form_fill"]
-evidence = ["crates/forms/src/af/tests.rs::validation_and_calculation", "crates/forms/src/tests.rs::formats_validation_and_calculations_run_like_acrobat", "crates/automation/tests/it/automation.rs::form_formats_and_calculations_through_tools"]
-notes = "AFRange_Validate with Acrobat's messages"
+evidence = ["crates/forms/src/af/tests.rs::validation_and_calculation", "crates/forms/src/tests.rs::formats_validation_and_calculations_run_like_acrobat", "crates/forms/src/tests.rs::unsupported_first_validation_call_preserves_custom_script_dispatch", "crates/automation/tests/it/automation.rs::form_formats_and_calculations_through_tools"]
+notes = "AFRange_Validate with Acrobat's messages; unsupported arguments in the first genuine call preserve the complete custom script for the supplied interpreter, rather than selecting a later literal call (save/reopen and validation dispatch covered)."
 
 [[feature]]
 id = "form.af-simple-calculate"
@@ -5268,7 +5268,7 @@ status = "shipped"
 commands = ["form.prepare"]
 tools = ["form_set_props"]
 evidence = ["crates/forms/src/tests.rs::locked_fields_only_take_unlocking", "crates/ui-egui/tests/it/prepare.rs::preview_fills_the_form_and_locked_fields_keep_their_properties", "crates/forms/src/tests.rs::renaming_a_kid_is_checked_against_the_full_name_it_takes", "crates/forms/src/tests.rs::renaming_a_top_level_field_is_still_checked_against_top_level_names", "crates/forms/src/tests.rs::dotted_field_names_are_made_with_parent_fields"]
-notes = "rename in Field Properties ▸ General, which shows the full name; a dotted name (MASTER.first) is a full name and makes or joins parent fields, as Acrobat does, moving a renamed field with what it inherited (#2696); Prepare a form's table tool still refuses a period in the cell names it makes; a plain name renames the field within its parent, so the GUI cannot yet move a nested field to the top level; Locked sets the widgets' annotation Locked flag (/F bit 8) and greys out the properties until unlocked; values can still be filled in"
+notes = "rename in Field Properties ▸ General, which shows the full name; a dotted name (MASTER.first) is a full name and makes or joins parent fields, as Acrobat does, moving a renamed field with what it inherited (#2696); inherited checkbox/radio export options survive a move and save/reopen, while choice fields keep only their own options; Prepare a form's table tool still refuses a period in the cell names it makes; a plain name renames the field within its parent, so the GUI cannot yet move a nested field to the top level; Locked sets the widgets' annotation Locked flag (/F bit 8) and greys out the properties until unlocked; values can still be filled in"
 
 [[feature]]
 id = "form.tab-order"