English term (edited): to a T

http://en.wiktionary.org/wiki/to_a_T
Etymology

The origins of this phrase are uncertain, but it has been observed in print since at least 1889, and likely was around well before that. The potentially related phrase "to a tittle" is found in a 1607 play, The Woman Hater by Francis Beaumont and John Fletcher ("I'll quote him to a tittle"). The T in the phrase to a T is likely the first letter of a word, with tittle being the most likely source.

Other theories with little evidence point to golf tees, for their small size; this may have at least influenced the alternate form to a tee. Some speculate a relationship with T-square, a measuring device introduced around the turn of the century. Others claim the expression refers to the correct completion of the letter t by crossing it.

Adverb

to a T (not comparable)

(idiomatic) Precisely; exactly; perfectly; with great attention to detail.

The announcement of the political endorsement was timed to a T.
The colors of your suit fit you to a T.