All reports of doubly-armored-upstream-signature for the archive. The extended description of this tag is:
The packaging includes a detached upstream signature file that was armored twice (or more) using gpg --enarmor. That is an error.
Please armor the signature just once. You can also use standard tools such as gpg --armor --detach-sig.
This tag has not been emitted in any package tested by Lintian.