/usr/share/lintian/overrides/libdb5.3 is in libdb5.3 5.3.28-3ubuntu3.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 | # historical reasons
libdb5.3: package-name-doesnt-match-sonames libdb-5.3
|