
This phone number 98+765432 satisfies the logical constraints of the UG:

However, the app forbids it. This can be fixed both as a functionality bug or documentation bug, depending on preference. I think the code actually doesn't support the constraints given in the table, and what you meant to put in the UG was '+ can only be at the start of the phone number', which was a crucial oversight. But on paper, because there is a mismatch between "functionality" and advertised behaviour, I'm putting this nominally as a functionality bug.
ADDITIONALLY, the examples given doesn't do anything to disprove that an infix + wouldn't be allowed.

This phone number
98+765432satisfies the logical constraints of the UG:However, the app forbids it. This can be fixed both as a functionality bug or documentation bug, depending on preference. I think the code actually doesn't support the constraints given in the table, and what you meant to put in the UG was '+ can only be at the start of the phone number', which was a crucial oversight. But on paper, because there is a mismatch between "functionality" and advertised behaviour, I'm putting this nominally as a functionality bug.
ADDITIONALLY, the examples given doesn't do anything to disprove that an infix

+wouldn't be allowed.