46 C.F.R. § 50.10-30 – Coast Guard number.

(a) The Coast Guard number means that number assigned to boilers and pressure vessels by the Officer in Charge, Marine Inspection, who makes the final tests and inspections.
(b) The Coast Guard number must be stamped on the nameplates of boilers and pressure vessels.

(1) Three capital letters which identify the office of the issuing Officer in Charge, Marine Inspection (see table 1 to § 50.10-30); followed by,

(2) An OCMI serial number, by which the particular boiler or pressure vessel can be identified; the first two digits of which will identify the calendar year the number was assigned.

Table 1 to § 50.10-30—Previous Sector Office Identification Letters in Coast Guard Numbers for Boilers and Pressure Vessels
Identification	SectorOffice
ALB	Albany.
ANC	Anchorage.
BAL	Baltimore.
BOS	Boston.
BUF	Buffalo.
CHA	Charleston.
CHI	Chicago.
CIN	Cincinnati.
CLE	Cleveland.
COR	Corpus Christi.
DET	Detroit.
DUL	Duluth.
GAL	Galveston.
GUA	Guam.
HON	Honolulu.
HOU	Houston.
HRV	Hampton Roads, VA.
HUN	Huntington.
JAC	Jacksonville.
JUN	Juneau.
LIS	Long Island.
LOS	Los Angeles.
LOU	Louisville.
MEM	Memphis.
MIA	Miami.
MIL	Milwaukee.
MIN	Minneapolis.
MOB	Mobile.
MOR	Morgan City.
NAS	Nashville.
NEW	New Orleans.
NYC	New York.
PAD	Paducah.
PAT	Port Arthur.
PHI	Philadelphia.
PIT	Pittsburgh.
POM	Portland, ME.
POR	Portland, OR.
PRO	Providence.
ROT	Rotterdam.
SAV	Savannah.
SDC	San Diego.
SEA	Seattle.
SFC	San Francisco.
SIM	Saint Ignace.
SJP	San Juan.
SLM	St. Louis.
STB	Sturgeon Bay.
TAM	Tampa.
TOL	Toledo.
VAL	Valdez.
WNC	Wilmington, NC.

[CGFR 68-82, 33 FR 18808, Dec. 18, 1968, as amended by CGFR 69-127, 35 FR 9975, June 17, 1970; CGD 74-219, 39 FR 40158, Nov. 14, 1974; CGD 78-161, 44 FR 13492, Mar. 12, 1979; USCG-2000-7790, 65 FR 58459, Sept. 29, 2000; USCG-2006-25556, 72 FR 36330, July 2, 2007; USCG-2020-0634, 89 FR 50094, June 12, 2024]