Caves don't get mapped (especially big ones) if people don't participate in the survey. I list everyone who has participated, no matter what their level of involvement - and I just list all surveyeors alphabetically. I've inducted many a non-surveyor on mapping trips - telling them that all they had to do was hold the end of the tape for a few stations to get their name on the map. This method has proven quite successful in getting survey projects finished - and thats the point isn't it...map the cave and credit everyone who helped. If you want people to keep contributing to a survey project the way to keep them coming back for more is to provide them with up-to-date maps and/or line plots and topoverlays. Promises of map credit don't always inspire - tangible in-hand results do.
For a resurvey project, I also list those who participated in the original surveys (though under a separate heading). If I use photos on the map, the photographer/s and their assistants get credited (if the photographer tells me who they are).
For those folks who like to find and explore caves but not map them...if you want credit for that, submit your discovery to the local cave survey, publish trip reports ,and give presentations at grotto or other caver related meetings. If you don't want to get scooped on your new discovery then don't broadcast it until you're finished - though there is always the risk that someone else is doing same and may beat you to it (yes, its happened!)
Though mapping/exploring caves in a one step process is the "preferred" method - its not always feasible. And as long as the cave gets mapped at some point does it really matter? For ridgewalking I always take along mapping gear, GPS and camera. If I find something that "seems" insignificant, it can be mapped immediately, gpsed, entrance photographed etc. All of this is important info to add to the exploration of a caving/karst area - even the small ones might be important even if you don't recognize it immediately.
pk