hehhehehe, no MD, certainly one of my chosen areas of complete ignorance.

I use the following:

J - Jumpers, Headers, Connectors
P - Componentless Pads

I never really saw much use in different names for male and female connectors and never really paid much attention to those reference designators in others' schematics.

Personally, I've always used the refdes J for all connectors. To me they're just JUMPERS of what ever sort.

I got my J & P flipped the following way which I'll probably keep but I appreciate your assistance in identifying the standard.

I have a connectorless motherboard in our assembly that mates with two right angle male jumpers from two other PCBs. The assembly is glued togother and then joined at a wave-solder "fountain" attachment.

When laying out the PCB, I gave the refdes J for the Jumper version of the PCB footprint and P for the Pads Only footprint which is a connector pad layout with no associated component and no component "keepout" zone.

The PCB layout still needs those mating pad sites to be layedout matching the pin pitch of the connector to mates it.

So, I ended up with:
J - Jumper
P - Pad

It works for our assembly and there will be no P components inserted during assembly.

aka J - for Jumper