Short bio: Computer Scientist, FOSS supporter (read more)
Tux Machines (TM)-specific
For most people, Microsoft Office Word is synonymous with word processing in general. They do not know or care that there used to be software like WordPerfect, or that some people run LibreOffice, AbiWord, and many other programs. For them, .doc is all they know and will ever open. Do not even try to tempt them with .rtf files, you might get into some serious trouble.
In this reality, you must work with such people, sometimes, if the count of affected users exceeds one. You might be forced to send them your text documents. And when I say text, it means a binary format of some kind used by a word processing software. And when I say word processing, I mean Word. Microsoft, Office, Word.