[TheRealPomax]

This sounds like it's not actually true? If it was, the French code page 646 that we used until Unicode finally won would have included a narrow space, but it doesn't. "Regular" computer text in French has only ever used a normal space, even if handwriting and/or "true" typesetting using typesetting solutions like TeX or PageMaker etc. allowed for a narrow space.

[pcdavid]

FWIW, LibreOffice automatically inserts an actual Unicode NO-BREAK SPACE when I type ":" at the end of a word (if the language is set for French of course). If I insert an actual SPACE and then hit ":", it even replaces the SPACE with a NO-BREAK SPACE.

I'd be surprised MS Word doesn't do the same. No need for a "true" typesetting solution.

[rodelrod]

I think the point of the GP is that it inserts NO-BREAK SPACE instead of a NARROW NO-BREAK SPACE. If that's the case, it's a bug.

[bombcar]

Codepages are from back in the era of little memory available and monospaced fonts.

And another "US English" centered thing; spacing does not really matter in English, but can have functional differences in other languages and scripts.

https://www.youtube.com/watch?v=2yWWFLI5kFU is a fun look at one of the problems with Unicode in general.

[dieulot]

This? https://en.wikipedia.org/wiki/Code_page_1010 There’s no space for it nor for many other more useful characters (like â).

[rodelrod]

This is mostly correct, but I don't see how it contradicts my statement.

Did the 646 standard account for variable-width characters at all?

[TheRealPomax]

Not so much contradict as wondering about the claim that it should be a specific Unicode codepoint when Unicode wasn't around when we started "computering" text (and the Académie Française can't have possibly formally declared things in terms of Unicode =)

What are the actual official rules in this case (and are there links to those? Because that'd be fascinating information to read through)?

[rodelrod]

Best reference I could find is here: https://www.lalanguefrancaise.com/articles/espace-insecable

Actually before the ":" specifically there should be a regular non-breaking space, not a narrow one. Except in Switzerland. Other punctuation marks take the narrow non-breaking space.

[TheRealPomax]

Love how it's "recommandé", "pour des raisons esthétiques."

Which I guess means we're completely free to ignore it. Pour mêmes raisons =P