impulse! (jazz label active during the 60s-70s, now property of Universal Music Group, mainly used as a reissue label.)

"The new wave of jazz is on impulse!"

One of the mythic names in the jazz industry, impulse! has been known as "the house that Trane built".
The first activity period under ABC is the glorious one - covering the 60s until 1974 - with an emphasis on free jazz.
New production eventually faded out during the late 70s, though ABC continued to print reissues.
Sold to MCA in 1979, it was almost silent until being folded in under GRP in 1990, which eventually became the Verve Music Group. It has since been mainly reissuing its own stuff only - with a few exceptions: a handful of remix releases and commercial jazz stuff, a few new releases by artists with ties to the former impulse!, and a serie of new compilations and anthology box sets.
This reissue campaign intensified starting 1995, with enhanced/remastered reissues, etc.

Sleeves have a distinctive black and orange design, and sparse liner notes.
Note the label name is correctly capped as "impulse!" (see logos for symetry between "i" and "!").
Catalog numbers were as follow:
* First period: A # (mono) AS # (stereo) AQ # (quadraphonic, not all releases) with # from 1 to 100, then appending a 9 (eg: 9101 up to 9361). Two discs sets used an additional /2. There is a promotional (AS 1974) as well, and a rare 29000 serie (29065 to 29073)
* 1980s: MCD, MCAD
* 1991-1995: prefix GRD optionally followed by one digit (number of discs in the set) followed by a three digit catalog number. Example: GRD2113 (3 discs set)
* 1995-1999: prefix IMPD optionally followed by one digit (number of discs in the set) followed by a three digit catalog number. Example: IMPD8280 (8 discs set)
* 1999-2003: used a subset of the barcode. Example 3145479582 for 731454795821
* 2003-*: prefix B, followed by three zeros, followed by a four digits cat #, followed by 02 for CD, 16 for SACD. Example: B000427002
* some rare Universal Japanese release used cat # like UCCI-####

For a more indepth history, you may consult The House That Trane Built: The Story of Impulse Records, Ashley Kahn, 2006, W.W. Norton.

Yet unconfirmed:
Note that there appear to exist 7" EP releases for some (?) of the 12".
Currently spotted: at ebay at discogs
Or even reel-2-reel EPs: at ebay
They don't seem to bear a distinctive cat #...
More:
at ebay
at ebay
Shirley Scott Everybody...

Notes:
Don't forget to sort out the Jasmine reissues.