For whatever reason, SureFire call their Clickie TailCaps "Charlie" TailCaps.
One reason could be because the MU Series uses a "C" to identify the SW02 switch. "P" identifies the SW01 TailCap Pressure Switch, and "UUxx" identifies the Tape Pressure Switch ("xx" is the length of wire between the 2.25" long (Add "L" for a 5" long version) Tape Switch and the TailCap, in inches - usually "06")
This of course is not the same as the "C" used by the handgun WeaponLights to identify the models with SlimLine Switch & Constant-on Shuttle Switch. For your information the models with SlimLine Switch & Disable Shuttle Switch are identified as "D".
To make matter easier, the Shotgun Forend WeaponLights use "FA" to identify Pressure Switch & Constant-on Rocker Switch, and "FGA" to identify Pressure Switch & Disable Rocker Switch.
So you think you follow?
The H&K Forend WeaponLights use "F" to identify Pressure Switch & Constant-on Rocker Switch, and "G" to identify Pressure Switch & Disable Rocker Switch.
I think perhaps "Charlie" is used because it is different in operation to a toggle click switch.
Regards,
Al