from Wiktionary, Creative Commons Attribution/Share-Alike License
- adj. Of a character, combined with another and so not consuming additional horizontal space.
Sorry, no etymologies found.
I don't have any personal data comparing spacing versus non-spacing but for me the spacing works well as a marker.
Stripping is an interesting job (aka On the meaning of meaningless, aka All Mn characters are non-spacing, but some are more non-spacing than others)
These are characters that are either non-spacing combining marks or zero-width control characters.