Nicki said:In the UK it is a legal requirement to put YOUR name and address on the tag.
It's also sensible to put contact numbers.
if possible put that they are neutered and chipped {you can get separate special tags to show this}
I would advise against putting the dog's name on the tag - if someone is trying to take them, and they can read the name, it makes it easier for them to call them away. Also if there is then a dispute over ownership, and you have to prove ownership, if you call the dog by its name and it comes running to you that is very helpful.