A,B, P etc

[Rdutton]

Does anyone know or have a link that explains what exactly the values for A,B, F, P etc represent in a sight reduction?

 I was asked recently and I know anything with H has to do with altitudes and the Zs are azimuths but the rest I don't know with enough certainty to pass on.

Thanks

BigBill,

Just a guess but maybe the P stands for the elevated Pole as in the geographical North pole projected into space?

I know there are the A, B, C tables and perhaps that applies to Nories?

Roland