The silent breaker, the type you can rely on to be late, or to not deliver on their promise - without letting you know until the agreed time has passed. Annoying.
The vocal breaker, the person you just know will let you down, but will tell you they are about too. It's too late for you to change your plans, you'll get text when you are waiting where agreed to meet for example.
The seletive keeper, this person may or may not keep their commitment, depending on how much they respect / fear / love the person they made it too. Better but still out of integrity.
The keeper who just does what they say they are going to do, no excuses, no praise needed.
...so, where do you sit on this ladder? Have you noticed any other types? What do you think it takes to move up a level?