I am assuming we are talking about ASME IX here.
SA516 GR70 is assigned P-No 1, testing on this material qualifies P-No 1 to P-No 11, P-No 34, P-No 41 to P-No 49.
Note this is 3 groups of material.
Qualifing on any one of these materials entitles the welder to weld them all.
I have never heard of P-No 15F
This may be a grade number from another code.
If we are not talking about ASME IX