eariler I was searching for a reference for the different "classes of variables"

Now I realize this is not a very common any more. The terms seems to leak out of the older professors minds now and then and pop-up in the news groups now and again but I can't seem to find any internet resource on the issue.

For example I know there are:
sentinels -- hold state and are used to control program flow
counters -- count the number of iterations/recursions
pointers -- hold addresses
accumulators -- used to accumulate a value in a iterated calculation
carries -- used to carry information from one iteration into the next

and I think:

data - holds a value/result.
atom -- (? increments in 1 instruction ?)

anyway. I know these kinds of terms are well out of fashion but if I was wondering if anyone had run across someplace that may have a more crystallized definitions and perhaps the other classes (I know there have to be more than this).

as it is I can't find these properly defined on the net. (sentinels for example are only referred to in the context of a loop where they clearly have many other uses).

What I am really looking for is a fuller list to help me refresh my memory. I am pretty sure that anything on this would be pretty old.