One more time, how dose copywrighting work?

[Rollermacka]

I made a topic discussing how TNA can do "Stone Cold" Sharkboy and "Macho man" Jay Leathal but one more time how dose a company copywright a name/ gimmick? I uderstand that gimmicks like the BWO or Gillberg were parodys so there isnt much they could do about them but how is it that Kamahla and "Macho man" Randy Savage can keep there name and gimmick in Savages case through at least three diffrent comanies but Tenta couldnt be Avalanche in WCW and Bubba Rogers couldnt be called The Boss because they were too cose to the gimmicks they used in WWF? Another thing I was wondering is how can a company copywright a name that's really just a word? Kinda like how he legally changed his name to Warrior to use the gimmick in other companies where the "Ultimate Warrior" name but how can you copywright something like that or how BG James couldnt be Outlaw in TNA because it was too close to what he did in WWE. Is it like saying I wasnt to be a wrestler called Havoc with green and black face paint, could TNA sue be and say they own that name, or could WWE if I wanted to be called Wrath or Rage?