Key to LIGO Document Numbers
c yy xxxx- vv- g

c

This position indicates the document category.

D
 Engineering drawings, CAD outputs.
E
 Engineering documents such as material lists, specifications, documents submitted to design reviews, parts lists, document change notices, and process travelers.
G
 Viewgraphs for presentations, photos, multi-media, sketches, etc.
L
 General correspondence (letters, memos, faxes) that do not belong in another category.
M
 Management Policies and Procedures plus M.O.U's and attachments.
P
 Formal physics or technical notes intended for publication and reviewed by the LIGO Project; student theses.
T
 Informal technical notes used internally or released but not intended for publication and not considered reviewed by the LIGO Project.
yy
 This 2-digit position denotes the year of issue of the original document. If a document is reissued in a later year with revisions, it retains the year of the document it supercedes. For the year 2000, this position reflects "00."
xxxx
 This is a four-digit sequential number. Each document category has its own sequential number.
vv
 This two-digit position reflects the version of the document. For uncontrolled documents, the first issue defaults as "00." In controlled documents, draft documents are numbered with sequential numbers, i.e. 01, 02, etc. A formally released final version uses alpha designators, i.e. A, B, etc.
g

This last position is used to identify the group from which it originates or group it pertains to. These group identifiers are as follows:

A
 Administration
H
 Physical Environment Monitoring
R
 Research & Development
B
 Beam Tube
I
 Interferometer
S
 Support Equipment
C
 Control & Data Systems
L
 Livingston Observatory
V
 Vacuum Equipment
D
 Detector Group
M
 Project Management
W
 Hanford Observatory
E
 System Engineering
O
 Conventional Construction
X
 Process Travelers
F
 Facilities Group
P
 Project Controls
Y
 Record of Decision (RODA)