collar for a sub

Im curious what some Doms and subs think being collared means. To me its almost like a wedding band and others think its just a gift from there dom ..If im talking to a sub and she tells me she is collared i cease any reference to talking about being her DOM .and yet She keep talking like she is free to as she pleases
And some Doms will continue talking to a collared sub as if it means nothing even if the subs Dom informs him that she is his property. Seems there are no gentleman Doms left or subs that take being collared serious .