/usr/share/lintian/overrides/php-htmlpurifier is in php-htmlpurifier 4.3.0+dfsg1-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 | # these also contain usage information
php-htmlpurifier: package-contains-upstream-install-documentation usr/share/doc/php-htmlpurifier/INSTALL.fr.utf8
php-htmlpurifier: package-contains-upstream-install-documentation usr/share/doc/php-htmlpurifier/INSTALL.gz
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