Semi-serious questions about reenactment

[Marcus Velius Avitus]

For the question regarding tatoos. Isn't it possible that the mysterious "mark of the legion" that ancient historians refer to recruits being marked with could have been a tatoo of some kind? Some think it may have been a brand - ouch! The Celts tattooed the heck out of themselves. Ancient people decorated thier bodies frequently. Not to mention that depending on when you are portraying, the empire may have been more or less homogeneous. That is, there may have been more cultural blending at one point over another?

Anyone have any suggestions or comments?