Triangle usually means Major 7. Where do you see the "p"? It depends on how it is being used.

I think you might mean "perfect" for intervals, like P1, P4, P5 ? Is that what you mean?

In Western music theory, the most common naming scheme for intervals describes two properties of the interval: the quality (perfect, major, minor, augmented, diminished) and number (unison, second, third, etc.)

@robert ok that 's right. Thank you.