if you save a docx file which contains style names with e.g. german Umlaute (Ü, Ä, Ö) with libreoffice writer, the stylenames are converted wrong.
A style name called "Überschrift" will be converted to "Üdcberschrift" if you view the RTF in ms word.
In the RTF File you can see the stlye name is \u220\'dcberschrift.
It looks like the hex code of the char is appended too.
I confirm it with
Version: 126.96.36.199 (x64)
CPU-Threads: 4; BS: Windows 10.0; UI-Render: Standard; VCL: win;
Gebietsschema: de-DE (de_DE); UI-Sprache: de-DE
Steps to reproduce
1. Open document in writer that contains custom style with "Umlaute" in its name
2. Save file as rtf-file
3. Open File in MS-Word
Result: Umlaute in style names changed (for example from "Überschrift" zu "Üdcberschrift"