xml-core binary package in Ubuntu Bionic amd64

 This package creates the XML infrastructure directories and provides
 XML catalog file support in compliance with the current Debian XML
 Policy draft:
 .
   * infrastructure directories:
      - /etc/xml
      - /usr/share/xml/{declaration,entities,misc,schema}
      - /usr/local/share/xml/{declaration,entities,misc,schema}
 .
   * XML catalog schema: OASIS XML Catalog Committee Specification 1.0
 .
   * update-xmlcatalog(8): tool for maintaining the root XML catalog
     file and the package XML catalog files in the '/etc/xml' directory
     as well as local XML catalog files.
 .
   * dh_installxmlcatalogs(1): debhelper tool for installing local XML
     catalog files and registering XML entities in package XML catalog
     files and the root XML catalog file (requires debhelper package)

Source package