signature definition

1. A set of function symbols with arities.

2. <messaging> (Or sig) A few lines of information about the sender of an electronic mail message or news posting. Most Unix mail and news software will automagically append a signature from a file called .signature in the user's home directory to outgoing mail and news.

A signature should give your real name and your e-mail address since, though these appear in the headers of your messages, they may be munged by intervening software. It is currently (1994) hip to include the URL of your home page on the World-Wide Web in your sig.

The composition of one's sig can be quite an art form, including an ASCII logo or one's choice of witty sayings (see sig quote, fool file). However, large sigs are a waste of bandwidth, and it has been observed that the size of one's sig block is usually inversely proportional to one's prestige on the net.

See also: doubled sig, sig virus.

2. <computer programming> A concept very similar to abstract base classes except that they have their own hierarchy and can be applied to compiled classes. Signatures provide a means of separating subtyping and inheritance. They are implemented in C++ as patches to GCC 2.5.2 by Gerald Baumgartner .

FTP.

(01 Jun )

1. A sign, stamp, or mark impressed, as by a seal. "The brain, being well furnished with various traces, signatures, and images." (I. Watts) "The natural and indelible signature of God, which human souls . . . Are supposed to be stamped with." (Bentley)

2. Especially, the name of any person, written with his own hand, employed to signify that the writing which precedes accords with his wishes or intentions; a sign manual; an autograph.

3. <physiology> An outward mark by which internal characteristics were supposed to be indicated. "Some plants bear a very evident signature of their nature and use." (Dr. H. More)

4. <medicine> A resemblance between the external characters of a disease and those of some physical agent, for instance, that existing between the red skin of scarlet fever and a red cloth; supposed to indicate this agent in the treatment of the disease.

5. The designation of the key (when not C major, or its relative, A minor) by means of one or more sharps or flats at the beginning of the staff, immediately after the clef, affecting all notes of the same letter throughout the piece or movement. Each minor key has the same signature as its relative major.

6. A letter or figure placed at the bottom of the first page of each sheet of a book or pamphlet, as a direction to the binder in arranging and folding the sheets. The printed sheet so marked, or the form from which it is printed; as, to reprint one or more signatures.

Star signatures (as A, 1) are the same characters, with the addition of asterisks, used on the first pages of offcuts, as in 12mo sheets.

7. <pharmacology> That part of a prescription which contains the directions to the patient. It is usually prefaced by S or Sig. (an abbreviation for the Latin signa, imperative of signare to sign or mark).

Origin: F. (cf. It. Signatura, segnatura, Sp. & LL. Signatura), from L. Signare, signatum. See Sign.