The symbology of the collar is quite simple but is often confused or misrepresented as a means to impose one's will onto another. I have witnessed and have heard reports of this since the earliest days of learning about BDSM. Unscrupulous people who make themselves out to be Dominant have used and contributed to the perversion of the collar's symbology.
Their are only two rules which govern the collar.
1.) Only a Dominant can place a collar.
2.) Only the submissive who wares the collar may remove it.
At no time is the submissive bound by the collar in such a way that it is in opposition of her will. Their can exist no scenario in which the submissive is prevented from removing the collar.
The only reason the collar exist at all is to symbolize her submission to her Master. The submissive, at all times the collar is worn, is choosing to serve.
A Dom maybe upset by his sub for removing her collar, but this is because she by action is demonstrating her lack of trust. In my view if this occurs it is likely the Dom's fault, because he should have an understanding of her limits.
Having said that I must admit that I have pushed a girl or two into removing her collar. I did this as a teaching moment, to demonstrate to her how she was holding onto concepts or ideas which affected her decisions on a subconscious level.
One of the most difficult task for any Dominant is to lead a submissive down a path of difficulty and pain only to demonstrate that all of the pain and difficulty was purely self imposed.
The reality is that the collar can not, while used correctly, be used as a tool of abuse. However a good Dom, if he's cleaver and quick can use it as a tool of growth and benefit for the submissive.
A Dominant only exist while there is a girl who calls him Master.
J.M.Rott(Dom)