How does autocategorizing decides what to put where?

For example I have (on class-side) three methods
#example
#example2
#exampleClusters

after autocategorizing they end up being

#example in 'example' protocol
#example2 in 'examples' protocol
#exampleClusters in 'as yet unclassified' protocol

That seems really odd, shouldn't all of them be in the same protocol?

Also is 'example' or 'examples' the normative protocol?

Thanks,
Peter