[NTG-context] Concerning \installparameterhashhandler and family

Hi. Reading at mult-aux.mkxl, I've seen command handlers define, among others, \installparameterhashhandler, However, in files such as those related with symbol management, only \installparameterhandler and \installsetuphandler are. When writing basic modules, sometimes only the "raw" macros above are actually needed. So, what are "parameterset", "hashhander", "rootparameterhandler", etc. for? Where would they ease module writing? Thank you a lot and sorry for the long question. Best regards, Jairo