I really, don't know how to describe these, but in our Home Game, we use the GHOST TARGETS rules from TACTICAL OPERATIONS (Pg 100) with regards to ECM suites. To that end, we often find during a game needing to know who's units with ECM is running which of the following:
ECM
ECCM (counters ECM fields)
GHOST TARGETS
STEALTH (as a unit with Stealth armor also has ECM: BMM pg 115/TW pg 142)
To that end I designed and 3D printed a base addon for the minis that sport a holder in the front, and with my new CO2 Laser Cutter, I have now made little tokens to place in the front to represent which mode the ECM is set for currently.