POM - Programming On The Main  

Programming On The Main (POM) is a special form of programming in which the locomotive is programmed while it is in operation, i.e. the locomotive does not have to be standing on the programming track and does not have to be stopped. POM must be supported by the decoder in use (see decoder instructions) and only certain settings can be programmed using POM. POM cannot be used to read out values from a decoder / locomotive. 

Aside from this, POM is nothing more than the normal Programming of CVs