Universal Service Order Code (Usoc); National Electrical Code (Nec) - Cabletron Systems 100BASE-FX Cabling Manual

Relevant Specifications
The installation procedures of the EIA/TIA help to ensure that care is taken to
avoid cabling situations that are possibly hazardous or which can result in
degradation of the operating quality of the installed cable.
The EIA/TIA 568 specification details the minimum distance that cables may be
located away from sources of electrical noise, what types of power cables or other
telephony cabling the cables being installed may be next to, how the connectors
must be installed, and other aspects which affect the overall usability of the cable
for a particular purpose.
Full copies of the EIA/TIA 568 specification may be obtained from a technical
document seller or ordered directly from the Electronics Industries
Association/Telecommunications Industry Association.

Universal Service Order Code (USOC)

The USOC specification is similar to many EIA/TIA specifications, including
EIA/TIA 568. The USOC specification describes, among other things, the
construction and installation characteristics of a type of twisted pair cable. The
USOC specification deals with the same aspects of the installation process as the
EIA/TIA specifications, but provides slightly different guidelines.
Originally, the specification was drafted by the Bell System, and copies of the
USOC specification may be obtained from technical booksellers or those Regional
Bell Operating Companies (RBOCs) which provide specifications to customers.

National Electrical Code (NEC)

The National Electrical Code or NEC is an overall specification to which all
facility wiring of any kind in the United States of America must be held. As the
NEC is a higher-level standard than either the EIA/TIA or USOC specifications,
the two lower-level specifications are designed to be automatically in accordance
with the NEC.
3-2 Universal Service Order Code (USOC)