The names of the letters are rarely spelled out, except when used in compound words (for example "tee-shirt, deejay, emcee, okay, aitchless," etc.), derived forms (for example "exed out, effing, to eff and blind", etc.), and in the names of objects named after letters (for example "em (space)" in printing and "wye (junction)" in railroading). The forms listed below are from the Oxford English Dictionary. Vowels stand for themselves, and consonants usually have the form "consonant + ee" or "e + consonant" (e.g. "bee" and "ef"). The exceptions are the letters "aitch, jay, kay, cue, ar, ess" (but "es-" in compounds ), "wye", and "zed". Plurals of consonants end in "-s" ("bees, efs, ems") or, in the cases of "aitch, ess", and "ex", in "-es" ("aitches, esses, exes"). Plurals of vowels end in "-es" ("aes, ees, ies, oes, ues"); these are rare. Of course, all letters may stand for themselves, generally in capitalized form ("okay" or "OK", "emcee" or "MC"), and plurals may be based on these ("aes" or "As", "cees" or "Cs", etc.")"