0334&SA=U&EI=UW4BVETVXVGGBKCPGSGE&VED=0CCGQFJAD&USG=AFQJCNE-B6UTUCCTM8PEGAR9A_U_AFKSOQ is not a valid tag

The format for a tag can be found on the tags explained page. In short:

4 symbols long
using digits and uppercase letters
excluding the letter O in favour of the digit 0 (except that this rule didn't exist in the very beginning of the Stacks project)