I had a negative temperature being broken across a line at the minus sign, and thought to insert a special character that would not be seen as a hyphenation character. But there was no suitable character available via the Insert Special Character dialogue; nor can you find non breaking characters there (by typing "break" as the search string). I found via Google that I could insert a special non-breaking minus sign by typing Ctrl shift minus. To me it seems natural to be able to find and insert such special characters by using the Insert Special Character dialogue. I gather you can also insert other special formatting characters from the Insert-Formatting menu, but it might be helpful to include all special characters via the Insert Special Character dialogue. Anyway, please consider.
That is a "Formatting mark" and we already provide it on the main menu Insert -> 'Formatting Mark' -> 'Non-breaking Hyphen' in a font neutral form (drawing on fall back font). Not "visible" on the Unicode centric Special Character Dialog (SCD) when its Unicode point U+2011 NON-BREAKING HYPHEN is not a defined glyph in currently the active font. The UCS string name or codepoint *will* be found in the SCD when the active font has coverage of the glyph. Request is a duplicate of bug 139107, although alternative of providing a toggle of the SCD font map to show a composite map filled by os/DE fallback of available fonts on system. *** This bug has been marked as a duplicate of bug 139107 ***