All reports of debian-copyright-file-uses-obsolete-national-encoding for the archive. The extended description of this tag is:
The Debian copyright file must be valid UTF-8, an encoding of the Unicode character set.
There are many ways to convert a copyright file from an obsoleted encoding like ISO-8859-1; you may for example use "iconv" like:$ iconv -f ISO-8859-1 -t UTF-8 copyright > copyright.new $ mv copyright.new copyright
Refer to Debian Policy Manual section 12.5 (Copyright information) for details.
This tag has not been emitted in any package tested by Lintian.