https://help.libreoffice.org/7.5/ro/text/shared/01/02100001.html has this phrase: > regular expression "$1ful" in the Replace box This phrase makes *absolutely* no sense, and is creating additional confusion. By definition, *regular expressions* are *matching* patterns, which are used when *searching*. There is a related replacement string syntax, but replacement strings are *not* regular expressions, and their syntax is necessarily different from regular expression syntax. Users tend to expect that *regular expression syntax* would work in replacement field; and this incorrect phrase reinforces this misconception. It should be changed to something like simple > "$1ful" in the Replace box Additionally, it would make sense to separate *all* the discussion of what is legal in replacement to a separate table (including, e.g., related pieces of \n and \t), to emphasize that they have *different* syntaxes.
Agreed, this needs correcting and clarifying in a separate section. The linked ICU documentation uses the terms "capturing parentheses", "capture-group" and "captured data", but we don't use the term "captur*" at all in our docs. ICU doc words it as: > "Capturing parentheses. Range of input that matched the parenthesized subexpression is available after the match." and: > "The replacement text for find-and-replace operations may contain references to capture-group text from the find."
Pierre F committed a patch related to this issue. It has been pushed to "master": https://git.libreoffice.org/help/commit/3a192b621db3644d50544a64f56ac34909711f92 clarify match/replace. tdf#153212