Hello,
Welcome to the forum.
The topic of safewords is 100% ok to bring up. And it's an important one for folks moving into bondage play.
There is a fair amount of debate as to what words work best.
I've always been of the mind that simple is best. 'Red' for stop everything now, 'Yellow' for check on me. Some like to use Apple and Bananna.
The idea is that the word should be distinct and easy to say, even if the person using it is in a state of distress. The word should never be something that could be confused with the normal things that a begging person would say.
The poster that suggests 'Don't Stop' above, provides very bad advice, that could be harmful. Words like Please, Don't, Stop, Help, etc are all things that a person in 'good' distress might say as part of the enjoyment of the situation. You need to be able to tell when Stop means STOP RIGHT NOW, I HAVE A CRAMP! and Stop means GOD I HATE THIS IN A GOOD WAY KEEP AT IT! By haveing a safeword like Red, the first situation can be differentiated.
One chooses a short word like Red because sometimes on tiny word is all a person can get out. While saying I have a cramp, stop for a sec may well be possible, it's always good to have a fast ripcord just incase the person can't.
Myriads