How to register new item filter in authtypes.properties?

Rhythmyx Technical Discussion
1

For reasons that I don’t want to go into, we are still using 5.x contentlists in some of our editions, even though we are in Rx 6.5.2. However, we would very much like to use a custom item filter.

I wonder if there is a way to declare the custom filter in the authtypes.properties. When I try to publish, I currently get the following error:

The requested authtype value ‘102’ is not registered with the system in the config file: /home/tivocms/Rhythmyx/rxconfig/Server/authtypes.properties

THANKS