When a station is transmitting under the privileges afforded by an amateur service license granted by the Government of Canada or an amateur service license granted by any other country with which the United States has a multilateral or bilateral agreement, an indicator consisting of the appropriate letter-numeral designating the station location must be included in the station identification announcement. See 47 C.F.R. § 97.119

This indicator must be separated from the assigned call sign by the slant mark (/) or any suitable word that denotes the slant mark. When the station is transmitting under the authority of an amateur service license granted by the Government of Canada, the indicator must be included after the call sign (example: "VE3XX/W4").

When the station is transmitting under the authority of an amateur service license granted by any other country with which the United States has a multilateral or bilateral agreement, the indicator must be included before the call sign (example: "W4/IB4DX). At least once during each intercommunication ("QSO"), the identification announcement must also include the general geographical location as nearly as possible by city and state, commonwealth or possession (example: "W3/IB4DX Kent Island, Maryland " or "VE3XX/W4 Wallops Island, Virginia").

The station location letter-numeral indicators are: Alabama W4; Alaska KL7; American Samoa KH8; Arizona W7; Arkansas W5; Baker Island KH1; California W6; Colorado W0; Commonwealth of Northern Mariana Islands KH0; Commonwealth of Puerto Rico KP4; Connecticut W1; Delaware W3; Desecheo Island, PR KP5; District of Columbia W3; Florida W4; Georgia W4; Guam KH2; Hawaii KH6; Howland Island KH1; Idaho W7; Illinois W9; Indiana W9; Iowa W0; Jarvis Island KH5; Johnston Island KH3; Kansas W0; Kentucky W4; Kingman Reef KH5K; Kure Island, HI KH7; Louisiana W5; Maine W1; Maryland W3; Massachusetts W1; Michigan W8; Midway Island KH4; Minnesota W0; Mississippi W5; Missouri W0; Montana W7; Navassa Island KP1; Nebraska W0; Nevada W7; New Hampshire W1; New Jersey W2; New Mexico W5; New York W2; North Carolina W4; North Dakota W0;Ohio W8; Oklahoma W5; Oregon W7; Palmyra Island KH5; Peale Island KH9; Pennsylvania W3; Rhode Island W1; South Carolina W4; South Dakota W0;Tennessee W4; Texas W5; Utah W7; Vermont W1; Virgin Islands KP2; Virginia W4; Wake Island KH9; Washington W7; West Virginia W8; Wilkes Island KH9; Wisconsin W9; Wyoming W7.