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BELL SYSTEM PRACTICES
AT&TCo Standard
REFERENCE
SECTION 502-501-102
Issue 2, July 1971
502-, 510-, 511-, 515-, 555-, AND 558-TYPE TELEPHONE SETS
EXCLUSION
HOLD KEY
LINE AND
SIGNAL KEY
502
TYPE)
511 OR 515
510
555 OR 558
Fig. 1-502-, 510-, 511-, 515-, 555-, and 558-Type Telephone Seta
@) American Telephone and Telegraph Company,
1971
Printed
in
U.S.A.
SSP S02-S01-102·i02_1971-07·0l.jpg Scanned by Frank Harrell, (Cowboy Frank) Castle Rock, Colorado Jan 30,2012 00:00:41
Ll NE AND
SIGNAL KEY
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