Releasing the album without an official title has made it difficult to consistently identify. While most commonly called Led Zeppelin IV, Atlantic Records catalogues have used the names Four Symbols and The Fourth Album. It has also been referred to as ZoSo (which Page's symbol appears to spell), Untitled and Runes. Page frequently refers to the album in interviews as "the fourth album" and "Led Zeppelin IV", and Plant thinks of it as "the fourth album, that's it". The original LP also has no text on the front or back cover, and lacks a catalogue number on the spine.
rELEasiNg thE alBUM WithOut an oFfIcIAl tiTle hAs made It diFFicult to ConsiStently ideNTiFy. WhilE most coMmonlY callED LEd zeppelIn IV, atlantIC REcORDs caTaloGues have USeD The NamEs fOur sYmBols anD tHe fOUrth album. it has aLSo bEen rEfErReD tO As zOsO (whIch page's sYmbol AppearS to SpelL), uNtitled and runes. page frequently refers to thE aLbUm in interVIEWS As "ThE foURth aLbum" And "lEd ZEpPeLIN Iv", aND pLant thinks oF it as "the fOurth album, tHat's iT". THE originaL lp aLSo haS NO Text on tHe fRont Or back cOver, And lacKs a caTaLoGue nuMbER ON the spINE.