So at the moment we are able to track ISRC's on recordings.

The general concensous (from what i gather at least is):

• ISRC's are not the be all/end all to identifying a recording (even though they're inteded too) this is because record labels/distributors often mis-assign ISRC's to recordings
• ISRC data can be obtained
  • automatically from digital providers who track such information (like Spotify)
  • automatically from CD's where it is encoded
  • manually by looking it up in a related database, like PPL Repertoire Search

However, as someone who often adds this information I would think it might be helpful to be able to mark invalid ISRC's (either due to formatting, being completely made up or wrongfully assigned) within the recording edit screen.

At the moment to try and curtail this, I've been adding information as an annotation:

https://beta.musicbrainz.org/recording/827992de-69c5-4f34-8dae-6a34c3183f63

The way I'd see it is that the editing page has some kind of checkbox next to it to mark the ISRC as invalid, and a short text field for the reason why.

Then when rendered on the page, the incorrect ISRC's could be identified by the use of either a strike-through or small symbol that when hovered over, would show the reason.