phono cartridge capacitance adjustment?

I've just installed a new phono cartridge (Ortofon OM20) in an older
turntable (Harmon Kardon T-45) attached to the phono stage of an NAD
AV-713 reciever. The turntable has a "capacitance trim" setting, and
I'm not clear about what this does or how to set it. I have found a
capacitance range fro the cartridge, but no such stat for the receiver.
Any clarification would be appreciated.
.