IDing bats

[SamG]

OK, if anyone knows what I can do it's you guys.

I got my DD a new bat for Christmas. However, it is a popular (and desired) bat. What can I do to identify it as my DD's? I'm thinking along the following, please let me know if it's legal/illegal, and if you have any other suggestions:

1) Inititals or name written in Sharpie just above the grip (bat's green, grip's black).
2) Using colored electrical tape at the top of the grip (currently black, could use green, red, yellow, white, anything).
3) Use an engraver and put name or initials on the knob.

Thanks for the help.