We have data on four different alprazolam pills manufactured by Mylan Pharmaceuticals. All of them are indexed with "A" and three of them have a number: A1, A3, and A4. Surprisingly, the strengths of the pills don't change from less to larger in correspondence with the numbers:
Mylan A is alprazolam 0.25 mg,
Mylan A1 is alprazolam 1 mg,
Mylan A3 is alprazolam 0.5 mg,
Mylan A4 is alprazolam 2 mg.
As for description, A, A1 and A4 pills are white, and A3 pill is peach-colored. All of the pills are scored on the reverse side, with A4 pill having two criss-crossed scores (to be divided into four parts about 0.5 mg of alprazolam each).