Languages

• AT - Ancient Telerin
• CE - Common Eldarin
• Dor. - Doriathrin
• F - Finnish
• G. - Goldogrin
• Ilk. - Ilkorin
• Ir - Irish Gaelic
• It. - Italian
• Lat. - Latin
• N. - Noldorin
• NS - North Sindarin
• OE - Old English or Anglo-Saxon
• OHG - Old High German
• ON - Old Norse
• ON, ONo. - Old Noldorin
• PQ - Primitive Quendian
• Q. - Q(u)enya
• T. - Telerin
• W. - Welsh
• WS - West Sindarin

Central mythology

• LotR - The Lord of the Rings
• LotR App. - The Lord of the Rings Appendix
• Silm. - The Silmarillion
• UT - The Unfinished Tales

The History of Middle-earth

• LT1 - The Book of Lost Tales 1
• LT2 - The Book of Lost Tales 2
• LB - The Lays of Beleriand
• SM - The Shaping of Middle-earth
• LR - The Lost Road and Other Writings
• RS - The Return of the Shadow
• TI - The Treason of Isengard
• WR - The War of the Ring
• SD - Sauron Defeated
• MR - Morgoth's Ring
• WJ - The War of the Jewels
• PM - The Peoples of Middle-earth

Other books

• AI - J. R. R. Tolkien. Artist and Illustrator
• Let - The Letters of J. R. R. Tolkien
• MC - The Monsters and the Critics and Other Essays
• RC - The Lord of the Rings: A Reader's Companion
• Rgeo - The Road Goes Ever On: A Song Cycle
• TC - The Tolkien Companion

Journals

• PE - Parma Eldalamberon
• VT - Vinyar Tengwar

Parts of journals

• ENG - Early Noldorin Grammar (PE13:120-135)
• EQG - Early Qenya Grammar (PE14:35-86)
• Etym - The Etymologies (LR:341-400)
• GL - The Gnomish Lexicon (PE11)
• GLS - Gnomish Lexicon Slips (PE13:106-118)
• GV - Gnome Vowels (PE15:13)
• ND - Noldorin Dictionary (PE13:157-165)
• NW - Noldorin Word-lists (PE13:136-156)
• QL - The Qenya Lexicon (PE12)