Actually, the P stands for pre-war. similar to the guy who said low-profile, the pre-1945 Martins had a slim-line (low profile) neck. Post 1945 they began a thicker neck. It was then introduced as an option in the 80’s. Now all come with the low-profile neck. The HD-28 P’s are an easier playing guitar than the straight HD-28’s and actually resonate a little longer as the neck helps keep the resonance flowing between the nut and bridge. I have a D-28P and an HD-28P and think they are quite the cut above my other acoustics.

Mike T.

: I bought a 1987 Martin HD-28 P and was wondering if anyone could tell me what the "P" designates? I have ask a lot of people and noone has ever seen this before.

The P stands for low-profile neck . When Martin started to install low profile necks it was an Option but in the late 80s to early 90s they installed the low profile neck on all of its guitars. It now comes standard on all Martins.