Michael Quinion reports in his latest World Wide Words (#661, October 17):
TWINKLE, TWINKLE, LITTLE TWINK It's amazing what you can learn from e-mail error messages. The issue last week was blocked by one site in the UK because it had a rude word in the message body. Do you recall reading any rude words? I don't remember writing any. It transpired that the offending "word" was in the title of a nursery rhyme I listed: Twinkle, Twinkle, Little Star. The filtering system spotted the first five letters of the first word and pounced. I had to look it up: TWINK is gay slang (I quote Wikipedia) for "a young or young-looking gay man (usually white and in his late teens or early twenties) with a slender build, little or no body hair, and no facial hair."
From the Wikipedia entry, it's hard to see why anyone should treat twink as a rude word. In current gay slang, it labels one of a number of recognized "types" of gay men: twink, bear, clone, prep(py), leatherman, queen, jock, etc. Each is associated with a stereotype involving physical appearance, attitudes, and presentation of self, through dress, bearing, gesture, speech, and so on; there is a weak, but only a weak, association with preferences for sex acts and roles. The set of types is not a taxonomy of gay men; a great many gay men don't fall clearly within one of the types.
Within the world of gay men, the labels are taken seriously as social identifiers, but as is common with labels associated with social stereotypes, they're often used in a mildly mocking (even self-mocking) fashion.
But things are more complex than that.
Believe it or not, the OED (additions series 1993) has an entry for uses of twink, and twinkie as well, with reference to gay men. The etymology of twink is uncertain, though the OED hesitantly suggests a relationship to twink 'twinkling', and it notes a popular association of twinkie, and so twink as well, with the snack cake Twinkie (the OED doesn't go so far as to record jocular references to twink(ie)s as being, or getting, filled with cream).
Uses of twink(ie) with reference to gay men are fairly recent. The OED's first cite for twink is from 1963, but it's in an American Speech article reporting on word uses, so that the word surely has an earlier history. The first cite for twinkie is from 1980, again in a report on usage, this time in Maledicta.
The earliest uses are (mildly or strongly) derogatory, and seem to come mostly from straight people. The American Speech article glosses twink as 'an effeminate young man, a sissy', and gives it in the list of alternatives
pansy-ass, petunia, punk, swish, weenie
Eventually, we get to Armistead Maupin, a gay man, using twink non-derogatorily, as a label for a gay male "type". From More Tales of the City (1980:85):
I found this gorgeous twink carpenter in the Mission.
The OED glosses twinkie as 'a male homosexual, an effeminate young man; also, a child or youth regarded as an object of homosexual desire'. The cites are all at least mildly derogatory in tone, though by 1988 we get an American Speech article in which twinkie and clone refer to gay male "types".
NOAD2 lacks twink, and, like the OED, treats twinkie as a general term for 'a gay or effeminate man', but adds a more specific (perhaps too specific) gloss describing a "type":
a young gay male who is meticulous about his dress, hair, weight, and other aspects of his personal appearance
What's new in NOAD2 is a usage label, "informal offensive"; the OED merely labels twink and twinkie as "U.S. slang".
These dictionaries don't distinguish out-group and in-group use, but that's clearly significant. There's also variation in in-group uses; as is usually the case with social labels (and categories), attitudes towards the words (and the referents) differ from person to person. Here's a site (with descriptions of gay slang) that makes both of these points:
Twinkie or its more common abbreviation twink, are used as generic derogatory terms to describe a weak or effeminate male. In gay slang, twink is a term that describes a young or young-looking male, usually of slender build, only slightly muscular, with little to no body hair (often referred to as a "swimmer's build"). Often they are described as bleach-blond. To many gay men, the term is pejorative and implies shallowness and stupidity. There are also allusions to the Twinkie pastry, due to the analogy of the creme filling to a young gay male. Twinks are typically contrasted with bears. (link)
Note that twink(ie) picks up aspects of the "dumb blonde" stereotype.
None of this, of course, would justify filtering out e-mail that has the word twinkle in it, on the grounds that twink is a "rude word". Even if twink counts as taboo vocabulary in current English — a very dubious claim, it seems to me — the automated searching that picks out twinkle as a problematic word is inexcusable (another instance of the baleful Scunthorpe effect).