I recently helped someone figure out a situation where they were seeing a foundry’s custom not defined glyph instead of, well, just seeing the content they wanted.
It’s rare that end users will see your
.notdef not defined glyph when using your font, as hopefully they get a fallback provided by their operating system instead, but it is possible.
The conventional design, as I’m sure you know, is an empty, narrow rectangle. A type designer or foundry can decide to put what they want there, however.
That’s what happened in this case: there was a logo-like design element in place of your typical narrow box (empty, or with a slash, or a question mark, etc.)
I never had an opinion on novelty not defined designs before. If anything, I’d probably have been in favour of them, at least for display typefaces. The character is technically required, but the glyph should ideally remain unseen, so it feels like an opportunity for an easter egg.
Seeing how much it confused non-designers writing content set in this font, though, I’d have to have a compelling case for it in the future.
If you are able (and willing) to fit a “see here for support” message into 1000 UPM, though, I’d stay that more than qualifies!
Until next time,