char * XkbFindOverlayForKey (XkbGeometryPtr geom, XkbSectionPtr section, _Xconst char *under);
geometry that contains the section
section to be searched for matching keys
primary name of the key to be considered
Keys that can generate multiple keycodes may be associated with multiple names. Such keys have a primary name and an alternate name.
XkbFindOverlayForKey uses the primary name of the key, under, to look up the alternate name, which it returns.