This skips events that are integers or symbols.\n\
f -- Existing file name.\n\
F -- Possibly nonexistent file name.\n\
-k -- Key sequence (string).\n\
+k -- Key sequence (downcase the last event if needed to get a definition).\n\
+K -- Key sequence to be redefined (do not downcase the last event).\n\
m -- Value of mark as number. Does not do I/O.\n\
n -- Number read using minibuffer.\n\
N -- Raw prefix arg, or if none, do like code `n'.\n\