Acronym

=====Other conventions=====
When a multiple-letter abbreviation is formed from a single word, periods are in general not used, although they may be common in informal usage. "TV", for example, may stand for a ''single'' word ("television" or "transvestite", for instance), and is in general spelled without punctuation (except in the plural). Although "PS" stands for the single English word "[[postscript]]" or the Latin ''postscriptum'', it is often spelled with periods ("P.S.") as if parsed as Latin ''post scriptum'' instead.

The [[slash (punctuation)|slash]] ('/', or ''solidus'') is sometimes used to separate the letters in an acronym, as in "N/A" ("not applicable, not available") and "c/o" ("care of").

Inconveniently long words used frequently in related contexts can be represented according to their letter count as a [[numeronym]]. For example, "i18n" abbreviates "[[internationalization]]", a computer-science term for adapting software for worldwide use. The "18" represents the 18 letters that come between the first and the last in "internationalization". "Localization" can be abbreviated "l10n", "[[multilingualization]]" "m17n", and "[[accessibility]]" "a11y". In addition to the use of a specific number replacing that many letters, the more general "x" can be used to replace an unspecified number of letters. Examples include "Crxn" for "crystallization" and the series familiar to physicians for [[medical history|history]], [[medical diagnosis|diagnosis]], and [[therapy|treatment]] ("hx", "dx", "tx"). Terms relating to a command structure may also sometimes use this formatting, for example gold, silver, and bronze levels of command in UK policing being referred to as Gx, Sx, and Bx.