xhtml-relaxng 20131210+dfsg+1-4 (armhf binary) in ubuntu xenial

 This package contains an implementataion in RELAX NG of the modularization of
 XHTML specified by the Modularization of XHTML Recommendation
 .
 The RELAX NG schema has not been mechanically derived from the DTDs. Rather,
 it has been hand-crafted so as to produce a good quality RELAX NG schema.
 However, it may well contain bugs.