The 25 Cities Project Federal Interoperability Channels were developed through the Department of Justice “25 Cities” project to support local, state, federal, and tribal voice communications interoperability. Each metropolitan area has agreed upon policies and procedures regarding use of these channels. Most 25 Cities VHF channels are accessible by non-VHF users via permanent or ad hoc patching capabilities

The "SECTOR" callsign is the Customs National Law Enforcement Communications Center (NLECC) in Orlando FL. SECTOR has the ability to communicate with each and every remote USCS repeater in the United States through landline links. When someone keys their radio, they are connected to the appropriate geographic console, which is monitored constantly by a Sector Enforcement Specialist (SES) in Orlando. Other callsigns to keep in mind: - ALPHA callsigns are ICE agents. - LIMA callsigns are US Customs Air Assets, aircraft, or helos - INDA callsigns are US Customs Inspectors - The LIMA-950 callsign is the US Customs air operations center (C3I West) at March AFB in California. This center also has callsign HAMMER on HF, and is occasionally heard and used on the VHF network. - The LIMA-150 callsign is a local AOB (Air operations base) in Texas.

The Federal Reserve Bank of Dallas covers the Eleventh Federal Reserve District, which includes Texas, northern Louisiana and southern New Mexico, a district sometimes referred to as the Oil Patch