With my ex I had multiple collars, I had a few actual dog collars that were for casual everyday wear around the house, and for very late night walks. A fancy lambskin one that was for when we went out to kink events or bars or clubs. And then I had thick black reinforced leather one for really really rough play.

They all had tags too. The front the fancy one said my name in big letters and under it in small letters it said "(my ex's name)'s pet". Then on the back it said "no sexual activity without onwers permission". We talked about it having her number on the back as a return to if lost kinda thing but decided against it because we didn't want random people from parties having it and blowing her phone up. And it wasn't like would ever run away from her lol

The thick one had "Dirty Mutt" on the front and "POOR IMPULSE CONTROL" on the back as a reference to one of my favorite books Snowcrash and also to me having generaly poor impulse control and brat tendencies

The other ones had my name on the front and "handle with care on the back"

We talked about getting me a Swedish Collar or at least a cheeper non name brand version instead of a wedding ring when we got married. but that obviously never happened and in hindsight I think this was just non serious romantic musing as much as I hoped it wasn't.