United States Olympic Committee.
The USOC is an organization which helps organize the Olympic Games when they are hosted in a city within the USA. Most often, this organization promotes the "proper" use of any variation on the term "Olympic" by closing down long-established businesses who don't pay their licensing fees.
Universal Service Order Code.
A collection of standards for telephone communication including wiring, terminology, and protocols. RJ modular connectors (RJ-45, RJ-11, RJ-21X, etc.) are specified in USOC standards as are the coloring codes of telephone wires (see below for major specifications).
USOC Block Wiring
Wire Color T#/R# Pair # 50 Pin Pos 66/110 Pos
white/blue T1 1 26 1
blue/white R1 1 1 2
white/orange T2 2 27 3
orange/white R2 2 2 4
white/green T3 3 28 5
green/white R3 3 3 6
white/brown T4 4 29 7
brown/white R4 4 4 8
white/slate T5 5 30 9
slate/white R5 5 5 10
red/blue T6 6 31 11
blue/red R6 6 6 12
red/orange T7 7 32 13
orange/red R7 7 7 14
red/green T8 8 33 15
green/red R8 8 8 16
red/brown T9 9 34 17
brown/red R9 9 9 18
red/slate T10 10 35 19
slate/red R10 10 10 20
black/blue T11 11 36 21
blue/black R11 11 11 22
black/orange T12 12 37 23
orange/black R12 12 12 24
black/green T13 13 38 25
green/black R13 13 13 26
black/brown T14 14 39 27
brown/black R14 14 14 28
black/slate T15 15 40 29
slate/black R15 15 15 30
yellow/blue T16 16 41 31
blue/yellow R16 16 16 32
yellow/orange T17 17 42 33
orange/yellow R17 17 17 34
yellow/green T18 18 43 35
green/yellow R18 18 18 36
yellow/brown T19 19 44 37
brown/yellow R19 19 19 38
yellow/slate T20 20 45 39
slate/yellow R20 20 20 40
violet/blue T21 21 46 41
blue/violet R21 21 21 42
violet/orange T22 22 47 43
orange/violet R22 22 22 44
violet/green T23 23 48 45
green/violet R23 23 23 46
violet/brown T24 24 49 47
brown/violet R24 24 24 48
violet/slate T25 25 50 49
slate/violet R25 25 25 50
USOC RJ-61 8 Position/8 Wire Pinout
# Color T#/R#
1 White/Brown T4
2 White/Green T3
3 White/Orange T2
4 Blue/White R1
5 White/Blue T2
6 Orange R2
7 Green R3
8 Brown R4
USOC RJ-25 6 Position/6 Wire Pinout
# Color T#/R#
1 White/Green T3
2 White/Orange T2
3 Blue R1
4 White/Blue T1
5 Orange R2
6 Green R3
USOC RJ-14 6 Position/4 Wire Pinout
# Color T#/R#
2 White/Orange T2
3 Blue R1
4 White/Blue T1
5 Orange R2
USOC RJ-11 6 Position/2 Wire Pinout
# Color T#/R#
3 Blue R1
4 White/Blue T1
USOC RJ-31X Alarm Wiring
This connection is used so that an alarm system can be inline to the telephone system before premise wiring. When there is a need for the alarm system to make a call, it can sieze the line by disconnecting the premise wiring. Other times, the inner pair is connected directly to the outer pair.
# T#/R# Shorts To
1 R1 4
2 - n/c -
3 - n/c -
4 R 1
5 T 8
6 - n/c -
7 - n/c -
8 T1 5
For other wiring standards, see TIA/EIA-568-A and TIA/EIA-568-B. Most LAN cabling adheres to those standards, instead of the USOC telephone cabling system.
Legend
T#/R# = Tip/Ring #
50 Pin Pos = Position in 50-pin Centronix connector
66/110 Pos = Position in Type 66/Type 110 punchdown block
The 50-pin wiring table was created with a Perl script wrote by myself for use in various wiring situations. It was modified slightly to produce output suitable for E2.