/usr/include/ is in libhtmlcxx-dev 0.85-3.
This file is owned by root:root, with mode 0o755.
..
/usr/include/htmlcxx/
/usr/include/htmlcxx/html/
/usr/include/htmlcxx/html/ParserSax.h
/usr/include/htmlcxx/html/ParserSax.tcc
/usr/include/htmlcxx/html/ParserDom.h
/usr/include/htmlcxx/html/utils.h
/usr/include/htmlcxx/html/tree.h
/usr/include/htmlcxx/html/Node.h
/usr/include/htmlcxx/html/Uri.h
/usr/include/htmlcxx/html/CharsetConverter.h
/usr/include/htmlcxx/html/Extensions.h
/usr/include/htmlcxx/html/ci_string.h
/usr/include/htmlcxx/html/tld.h
/usr/include/htmlcxx/css/
/usr/include/htmlcxx/css/parser.h
/usr/include/htmlcxx/css/parser_pp.h