Capitol Custom

Capitol Custom Services (also Capitol Custom Services Department) operated two studios for recording, editing, tape dubbing and lacquer mastering/processing: one in Hollywood and one in New York City. Operative between 1953 and 1973.

Label and/or runout identifiers:
#B-nnnn-Ny% or #B-nnn (sometimes preceded by a 45-), where
# is a letter for the year (see below)
nnn / nnnn are numerics, e.g. 688 or 2287 (with consecutive 2288 on side B), and
y is a digit, e.g. 1 or 2 or 4 etc., and
% is a letter, e.g. C or D.

Examples:
45-GB-912-N1 / 45-GB-913-N2 (runouts), GB-912 / GB-913 (labels)
EB-2604-N1B / EB-2605-N1C (runouts), EB-2604 / EB-2605 (labels)

The letter preceding the B always signified the year of assignation of numbers, as follows:
CB = 1953
DB = 1954
EB = 1955
FB = 1956
GB = 1957
HB = 1958
JB = 1959
KB = 1960
LB = 1961
MB = 1962
OB = earlier 1963
PB = later 1963
RB = 1964
TB = 1965
UB = 1966
WB = 1967
XB = 1968
YB = 1969
ZB = 1970-71
AAB = 1971-72

Three digits in the matrix number (#B-nnn) usually signified numbers assigned out of New York, four digits (#B-nnnn) out of Hollywood. This was in effect for all speeds and formats (33 1/3, 45, 78, Mono, Stereo).