In sign language, an initialized sign is a word that is signed with a handshape that corresponds to the fingerspelling of the corresponding word in the locally dominant oral language, usually the initial letter of that word. In some cases, this is due to the local oral language having more than one equivalent to a basic sign. For example, in ASL, the signs for "class" and "family" are the same (a basic sign for 'group of people'), except that "class" is signed with a 'C' handshape, and "family" with an 'F' handshape. In other cases initialization is required for disambiguation, though the signs are not semantically related. For example, in ASL, "water" it signed with a 'W' handshape touching the mouth, while "dentist" is similar apart from using a 'D' handshape. In other cases initialization is not used for disambiguation; the ASL sign for "elevator", for example, is an 'E' handshape moving up and down along the upright index finger of the other hand.
The large number of initialized signs in ASL and French Sign Language is partly a legacy of Épée's system of Methodical Sign, in which the hand shapes of most signs were changed to correspond to the initial letter of their translation in the local oral language, and (in the case of ASL) partly a more recent influence of Manually Coded English.
Sign languages make use of initialized signs to different degrees. Some, such as Taiwanese Sign Language and Hong Kong Sign Language have none at all, as they have no manual alphabets and thus no fingerspelling. In ASL, initialized signs are typically considered "hearing" signs, used in schools to help students acquire English, though some such as "water" above are thoroughly assimilated. In Mexican Sign Language, however, initialized signs are much more numerous, and are more fully integrated into the language (Faurot et al. 1992). This is also the case with Nepali Sign Language, and are perhaps one of the most noticeable structural differences between the lexicon of Nepali Sign Language and that of neighboring Indo-Pakistani Sign Language, which (perhaps in part due to its two-handed manual alphabet) has significantly far fewer initialized signs, but a fair number of "sequential initializations (i.e. compound signs composed of the initial letter of the word either preceding or following a sign, e.g. "C" + BOSS = CAPTAIN in IPSL) (Morgan 2012).
^a Sign-language names reflect the region of origin. Natural sign languages are not related to the spoken language used in the same region. For example, French Sign Language originated in France, but is not related to French. ^b Denotes the number (if known) of languages within the family. No further information is given on these languages.