Common terminology or clear voice communications is something that is required under the National Incident Management System (NIMS). It will primarily effect the communications during an actual incident where the Incident Command System (ICS) is used involving multiple agencies.....however, in real-life, you are going to revert back to what you do on a daily basis....if you use 10 codes every day - it will be hard to instanly switch to clear voice during an incident IMHO. That is why a lot of people are talking about using clear voice daily.
From FEMA's FAQ page on NIMS:
"According to the NIMS: "Incident communications are facilitated through the development and use of a common communications plan and interoperable communications processes and architectures. This integrated approach links the operational and support units of the various agencies involved and is necessary to maintain communications connectivity and discipline and enable common situational awareness and interaction."
The ability to communicate within ICS is absolutely critical and using standard or common terminology is essential to ensuring efficient, clear communication. ICS requires the use of common terminology; that is, the use of plain English. Common terminology in communications is necessary to support mutual aid and the infusion of new responders coming to an event so they will be able to communicate with one another. All exercises that responders participate in should feature plain English commands so they can function in a multi-jurisdiction environment. Field manuals and training should also be revised to reflect the plain English standard. That said, it is the intention of the NIMS Integration Center to take a practical common sense approach to this, and not cut off funding to a city because we hear of first responder who happens use ten codes."
Another reference from FEMA's site:
NIMS Document Chapter V (B)(1)(b): "Incident Communications
These will follow the standards called for under the ICS. The IC manages
communications at an incident, using a common communications plan and an
incident-based communications center established solely for use by the command,
tactical, and support resources assigned to the incident. All entities involved
in managing the incident will utilize common terminology, prescribed by the NIMS,
for communications.
