When I rename them, I like to use the first two digits of the new name to designate the lake; for example, lake fork would be LF, then whatever other data I want, but usually just a 3 number sequence, like "LF001". I keep a notebook too to tell me what's there, but I usually don't need it because I remember the spot. I use the lake designation because I have lots of waypoints for many different lakes and this helps sort them for loading and unloading in the software I use.