Andy Lee has a interesting writeup based on the question posed by Peter Hosey:

what the longest symbol name (not selector) in Apple’s APIs?

Ken Ferry and Bavarious found this:

kCMSampleBufferConduitNotificationParameter_
UpcomingOutputPTSRangeMayOverlapQueuedOutputPTSRange

Yikes. Read Andy’s post to get more details on the search process, which includes code examples of searching the API’s.