If you're talking about XML elements, attribute names, and attribute values that you can use, your best bet is to read XML.txt and the comments at the end of buffs.xml. The other XML files may also have comments that explain things as well.
If that's not what you mean, then you'll need to be more specific. In programming-speak, the term "argument" means "the value you pass to some kind of procedure" and "parameter" means "the name and type of value that this kind of procedure accepts." They're not any more specific than that.