[MM3-users] How to store additional information about lists?

Hi together,

I need to add custom attributes to the mailing lists:

"responsible department": Free text field who is responsible from an organisational pov (not a person but an entity)

Enhance the boolean public to a tri-state: public, restricted audience and private (restricted audience means: some people could subscribe themself - how that works is a different topic but w/o the information this can't be achived) - of course this could also be implemented as a second boolean that e.g. splits "not public" into "restricted audience" and "private" (means: nothing goes wrong for code that doesn't know this difference).

Any hints how to do that best? Is it possible to store custom attributes, or should that be stored elsewhere?

Andi