We have divergence in the way we document function, operator and constructor constraints. About half use \note, while the other doesn't. Some say "if and only if" while others say just "participates only if". So add a qdoc macro, \constraints, to semantically mark up these constraints. It expands to a section titled `Constraints`, and uses a predefined sentence (prefix) for constraints. Documentation for constraints is moved to the end of the comment blocks to separate them from the rest of the text. Apply them to all the standard-ish constraint documentation blocks (grepped for "participate"). I didn't look for other, one-off, ways documentation authors may have documented constraints, but I'm also not aware of any. Re-wrap lines only if the result fits into a single line. As a drive-by, drop additional "if"s, as in "only if X and -if- Y" to make the texts work with the `Constraints` section. Fixes: QTBUG-106871 Pick-to: 6.9 6.8 6.5 Change-Id: I18c2f9f734474017264e49165389f8c9c7f34030 Reviewed-by: Kai Köhne <kai.koehne@qt.io> Reviewed-by: Paul Wicking <paul.wicking@qt.io> Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>