I have long theorized that it is inscrutable for a reason: as a bar to laypeople reading a/o editing prescriptions.

Turning "30 pills of Pennicillin, refill 0 times" into "30 pills of OxyContin, refill 3 times" is much harder when you can't even figure out which part is the drug name.

(Kids who are about to point out this couldn't work: Prescriptions used to be hand-written on paper, and never checked by the then-inexistent interwebs.)