P – Philology; Linguistic
- P1-85 - General
- P86-96 - Communication. Mass media
- P98-98.5 - Computational linguistics. Natural language processing
- P99-99.4 - Semiotics. Signs & symbols
- P99.5-99.6 - Nonverbal communication
- P101-410 - Language. Linguistic theory. Comparative grammar
- P306-310 - Translating and Interpreting
- P501-769 - IndoEuropean (IndoGermanic) philology
- P901-1091 - Extinct ancient or medieval languages
PA – Greek language and literature; Latin language and literature
PB - Modern European Languages; Celtic Languages
- PB1-431 - Modern languages
- PB1001-3029 - Celtic languages and literature
PC - Romance Languages
- PC1-400 - General
- PC601-872 - Romanian
- PC901-986 - Raeto-Romance
- PC1001-1977 - Italian
- PC1981-1984 - Sardinian
- PC2001-3761 - French
- PC3801-3976 - Catalan
- PC4001-4977 - Spanish
- PC5001-5498 - Portuguese
PD - Old Germanic and Scandinavian Languages
- PD1-780 - General
- PD1001-1350 - Old Germanic dialects
- PD1501-7159 - North Germanic. Scandinavian
PE - English Language
- PE101-458 - Anglo-Saxon. Old English
- PE501-693 - Middle English
- PE814-896 - Early Modern English
- PE1001-1693 - Modern English
- PE1128-1130.5 - English as a Second Language
- PE1700-3602 - Dialects. Provincialisms, etc.
- PE3701-3729 - Slang. Argot, etc.
PF - Dutch, Flemish, and German Languages
- PF1-5999 - West Germanic
- PF1-979 - Dutch
- PF1001-1184 - Flemish
- PF1401-1541 - Friesian
- PF3001-5999 - German
PG - Slavic Languages and Literature
PH - Finno-Ugrian, Basque Languages & Literature
PJ-PL - Oriental Languages & Literature
PM - American Indian and Artificial Languages