Can you ID in the middle of a match?

[homeofmew]

This came up yesterday when I judged A CC
Apparently according to what I was told, I made a bad call and said people can't.

I know one can concede at anytime. But let's say they are in the match and loosing asks winning player to ID?
Kinda seems uncalled for. Is there any documentation on this?

 

[PokePop]

The losing player can offer to ID.
That is the proper way to do it.
If the other player does not accept, they can't keep offering or asking.