Hello

I have now a question about the use of $b when I have 2 encoding formats for the same bib record.

So far, with no examples in the bib formats (LC or OCLC), I've been using two 347, one for each format that I have. Then I realized that $b is repeatable. So, what it is "correct" then?

347 ## $bPDF
347 ## $bEPUB

OR

347 ## $bPDF$bEPUB

Thanks for the guidance.

Keep safe

Ivan