"on the D.L."

[Mark A Mandel]

This is probably in the usual slang references, none of which I have on
hand, but in case not...

I am listening to a jazz program on WGBH radio -- I think it's "Jazz
from Studio Four" with Steve Schwartz -- and just now, about 8:50 pm, in
reading the names of the selections he had just played, he mentioned
that a listener had called in an explanation of this term. Apparently
the album was called _Blues on the D.L._, and in introducing it he had
said he didn't know what "on the D.L." meant.

A listener named ['vi:d@] called in and said that it is African-American
prison slang, short for "down low" meaning 'hush-hush': if you tell
someone something "on the D.L.", it is to be kept quiet.  Exactly
equivalent, then, to the obsolete(?) "on the Q.T.", which I have always
supposed came from the first and last letters of "quiet".

-- Mark A. Mandel
   Linguist at Large