I have always just put in one ear tag until 12 months, but maybe since they have introduced the separate slaughter tags that is not right anymore?
But that used to be the case.
Anyway, one tag in ear, 2nd tag in bag and ready to put in on request always worked. To be honest, I have never had any queries at shows so far...
Others have said that they had clearance form their local AH that pastern tag and tattoo is ok too, but not sure I have seen anything official...
I had a chat with someone about that at weekend, hopefully haven't advised anything too wrong...