On: I still use plain text for everything. (2016)

[asdff]

You can use pandoc to give them a word version

[imafish → asdff]

The formatting will not be pretty.

Source: I tried this.

[celeritascelery → asdff]

But what happens when they give you a modified version back?

[g8oz → celeritascelery]

pandoc -f docx -t markdown foo.docx -o foo.markdown

[asdff → celeritascelery]

You can just convert back