Emission designators are codes between 3 and 9 characters which describe a wireless signal.
In codes with at least 7 characters, the first four characters represent the bandwidth of the signal and the remaining characters describe the signal methods, modulation type used, and class of data being transferred. In older 3 character emission designators the bandwidth is not included in the code.
You can decode an emission designator and find some additional details with this simple form: