The whole point of marking up one's body is that it means something to the bearer of the marking.
- It could be a reminder of an event (personal meaning)
- It could be a statement of expectations or personal image. i.e. Raven's arm band that means "Princess". (Both in Chinese and Japanese characters, depending on the strip.
- Sometimes it just is just artistic, because the wearer liked the design.
- Or the wearer's significant other is or was a totoo artist and 'just got bored'.
And, let's face it, Jeph doesn't put ANYTHING into the strip that doesn't have meaning for him.