On Martin instruments such as the D35P and D28P, what does the “P” designation stand for?
The “P” was designated to distinguish guitars manufactured with low profile necks. This was done while Martin was manufacturing both full thickness neck guitars and low profile neck guitars on the identical models. The low profile (thinner) neck was introduced on the J40M in 1985 and was extended to some other models. The “P” designation was dropped when the low profile neck became the standard neck shape in 1991.
