Sometimes also referred to as QCA Custom Division.
Sometimes associated to "Q.C.A. Recording Studios", also known as QCA Studios.
Vinyl masterings can be identified by a QCA in the runout.
Vinyl pressings can be identified by the unique matrix numbers found in the runouts, e.g.
8104N3 = pressings until 1979
306081 = pressings from 1980 to 1983
607034X = pressings from 1980 to 1987
8X139 = pressings since 1988
The first number indicates the year, the next two digits indicate the month and the last three digits indicate the order number.
So, 306081 translates to: order no. 81, pressed in June 1983.
An X was appended in 1980 to indicate a two-step mastering process.
The later system was basically the same: 8X139 translates to order no. 39, pressed in January 1988 after a two-step mastering process.
Known mastering engineers:
Chuck Seitz (CS)
Don Schepmann (DS)
Donnie Kraft (DK)
Ken Martin (4) (KM)
Larry Ratliff (LR)
Mike Fuller (MF)
Ric Probst (RP)
Roger Seibel (RS)
Todd Deasey (TD)
Chuck Madden (CM)