Defining Personal Elements

I have asked a similar question here before but I am still having trouble figuring this out.

My question is how do I define personal elements - that is, elements with a name I created (and by extension, the text format rules in the EDD, etc.) - in FrameMaker so that they are recognized by FM? Is this simply a matter of naming them in the DTD/EDD as they are, or are there other steps involved in the process?

Thanks!