ParmID -what is it and Its use in formletter and salesFormLetter Class??

I would Like To know What is Parm ID how is it being Generated And What is its use in formletter and sale formletter class…As i am new to ax i would Like to Know.so can anyone please Help me…

Salesparm* tables are the intermediate tables used by the sales posting logic(for different sales order update statuses, normal and batch posting). Every update will be tracked with an unique id names parmId. look at the salesParmTable and salesparmLine.

ParmId is created in \Classes\SalesFormletterParmData\createParmTable using formletterParmData::getNewParmId();

Thank You So Much kranthi…

Vineesh.T