811.1/.9 All languages natural or artificial
 811.1/.8 Individual natural languages
 811.1/.2 Indo-European languages
 811.21/.22 Indo-Iranian languages
 811.3 Dead languages of unknown affiliation. Caucasian languages
 811.4 Afro-Asiatic, Nilo-Saharan, Congo-Kordofanian, Khoisan languages