Try to identify the lyric marked [?].
Aim to transcribe all audible lyrics. Use [?] only when careful listening still cannot determine what is being sung.
Example
[Verse]
I heard [?][Verse]
I heard every wordThe fix
This finding has no automatic fix — resolving it is a judgment call, so the workbench points at the exact range and leaves the edit to you.
Source
The guideline this rule enforces, as cited on every finding it reports:
Unknown lyric marker verified Use [?] for unknown lyrics