Commit https://git.libreoffice.org/core/+/82c3e68642de445064313e353812b54df76c7fe9%5E%21 of bug 118370 introduces the new feature "Consolidate Text". A new help text has to be written for it.
The purpose of this tool is, to ease editing of texts in PDF files.
For details read the commit message and the comments in bug 118370.
How to use it:
Select two or more text box shapes, open context menu and use item "Consolidate Text".
The command is available in macros via dispatcher as .uno:TextCombine. It has no parameters.
I can just say that we should always have to open a new documentation bug for a new feature.
Pity that Bugzilla doesn't support it as an extension, some subbug.