when using keytypes with annotationdbi I am presented with a vector of keytypes available in a given annotation package. I would like to get more documentation for unfamiliar keytypes. I can easily infer what SYMBOL refers to: RB1, THRB, etc. but others are less familiar. Is this information documented in help pages or anywhere else?

Trying ?AnnotationDbi::ACCNUM should get you a list of available values for 'columns' and 'keytypes' with their given descriptions. Hope this helps!