All reports of no-md5sums-control-file for the archive. The extended description of this tag is:
This package does not contain an md5sums control file. This control file listing the MD5 checksums of the contents of the package is not required, but if present debsums can use it to verify that no files shipped with your package have been modified. Providing it is recommended.
If you are using debhelper to create your package, just add a call to dh_md5sums at the end of your binary-indep or binary-arch target, right before dh_builddeb.
This tag has not been emitted in any package tested by Lintian.