IIRC, that one's for the context menu on a number, and you want to add
that to an existing contact, and you don't have any.
I heard statements from the email app about how they're having their own
UX guideline. Which I didn't find. I honestly didn't bother, I have an
email conversation with asuth that I need to follow up on anyway on
https://groups.google.com/d/msg/mozilla.dev.b2g/dgRjI_kxSCM/KKBj-Wnj1ZgJ
I agree, file a bug? I'd suggest to not change the ID here, though, this
is really just a typo.
Axel