All reports of spurious-fields-in-upstream-signature for the archive. The extended description of this tag is:
The packaging includes a detached upstream signature file that contains spurious fields like Comment: or Version:. They are sometimes added by gpg --enarmor, especially if you have an older version. Modern versions only add a Comment: field.
Please generate the signature with gpg --armor --detach-sig using a modern version instead.
This tag has not been emitted in any package tested by Lintian.