Vintage T-Shirt Forum & Community Authentication Appraisals

Hi guys,
First time I saw Anvil tag without size label on it. The size attached separately. Need help to find out what year this tag is.
Thanks.

i have had a nirvana in-utero shirt last few years and checked the anvil tag on it and its an anvil blue tag which means after 2000? does this devalue the shirt in any way would you describe it as reprint?