I love the
style of the Alexandrian figures, but find it funny how
poor their lettering usually is. Especially the
mint mark. I don't buy the idea that it is because they were likely not native Latin speakers. That would apply to all Eastern mints, and besides Greek speakers can write neat letters too. So it must be some sort of tradition there.
As for ties, I don't think there is any code. More a question of
mint style.
Antioch and
Alexandria seem to be the same. Both use three ties for large FTR and two ties for the small (
Phoenix) from the start in of the FTR coinage in 348 until the last few couple of reductions.
Antioch seems to then switch to two ties when the reduction from 1/72 L to 1/120 L occurs around November 353. (I am not absolutely sure of this as it is hard to see the details on some of these small
Antioch coins but I can't find one from the 1/120 L or 1/144 L series that clearly has three ties.)
Alexandria, however, has both three and two ties on the smallest coins. For example of my five FTR FHs from
Alexandria from the final (M) series I have three with three ties and two with two, and that includes two with three and one with two from the same
officina.
SC