Is there an ICSP pinout standard???

[richard]

I'd be concerned about potentially driving 13volts/Mclr onto the PGC/D pin if the 5pin header was reversed

can't happen with pk2 or pk3 those devices always ident chip and test voltage levels before pgm activity takes place

[pedja089]

Even if it try, current is low, and PIC esd diode should clamp max voltage on pin to Vdd+0.3V. So nothing to worry.

[tumbleweed]

i had no intention of using the VCC to provide power to the chip, so i was down to 4 pins myself

Even if you're not going to power the chip via ICSP it's important to provide the VDD connection.

That way the programmer can detect the target voltage, and for some programmers like the PK3 it uses that
target voltage to control the output voltage of the ICSPCLK and ICSPDAT signals.

This is esp. important if you work at lower voltages.

[pedja089]

You can set PK3 to supply same voltage as system, so pgd/pgc voltage should be OK. But again, 5 way pin header worked for me many years, so I don't see problem with that.
Recently I had small board with weird shape, and there was no room for 5 pin in row.
So I tried this
http://www.microchip.com/Development...tNO=TC2030-MCP
It is ok.