The used systematics for the climbable rocks is a genetic one. However nomenclature is not only based on genesis. It might be related to occurrence, geological age, minerals, size of grains, colour, technical use and much more. Aggravating there are transitions and peciuliarities of rocks which result in diverging names. Additionally there sometimes are misleading trivial names, trade names and so on. There also are diverging meanings of English and German terms and names. This might result in the fact that you do not find the most familiar name of the rock you climb on since years in the rock type list.
In case you are not sure about the tag, just use the higher category only, eg. 'Igneous Volcanic' or 'Metamorphic'.