What does PR and PE mean to left on contact name on my iphone

That likely means Primary number (PR) and Personal number (PE) for calls made with a dual SIM phone. Also see: Using Dual SIM with an eSIM - Apple Support

An screenshot image of your partial contacts list would be VERY helpful.

DO redact names / numbers or any other PII.

Added: I hope that’s indeed a “SIM Flag” as that would be a helpful feature for multi-SIM phones.

After some further experimentationexperimenting, the flags WILL show multiple letters IF the leading characters are identical. (as both were “P” in the OP)

That said I only see the flags in Messages and Recent Calls, but not Contacts.

That was my first thought too, but my contact list doesn’t display them, and AFAIK the SIM “Flags” are a single letter.