NPT is National Pipe Thread not to be confused with MPT which is a Male NPT – NPT could also be FPT (female). Don’t put the F at the end because then you’ll get NPTF which is Tapered Fine, a.k.a. Dryseal, although FPT and MPT can be used with NPTF without a problem. MPTF is male NPTF and can be used with NPTF, NPT, NPSM, and NPSH. NPSM is straight mechanical, not tapered. NPSH is straight hose. MPSH is go with FPSM and FPSH but FPSH is good with MPSM, MPT, MPTF, AND MPSH. BSPT is British Standard Pipe Taper, and can’t be used with NPT or NPTS. Meanwhile, NPS is Nominal Pipe Size not National Pipe Size and deals in schedules not threads not to be confused with NPF which is the National Psoriasis Foundation.
I really dislike Plumbing threads.