Option to use empty element syntax for contingently empty elements.
Check for ENTITY attributes whose value is internal CDATA/SDATA entity.
Option to generate IDREF attribute declarations.
Option to generate ENTITY attribute declarations.
Option to generate NOTATION attribute declarations.
Warn about characters unrepresentable in output encoding specified with -b occurring in contexts where numeric character references are not allowed.
Check for numeric character references to non-SGML characters.
Check for comments containing --.
Option to put link attributes on start-tags.
Check for invalid name characters.
Option to copy external entities to current directory.
Try to turn absolute filenames into relative filenames.
Allow SDATA names to be mapped to Unicode.
Output declarations in sorted order.
Option to use attribute defaulting.
Option to output reference to external DTD.
Option to use case that was used in the DTD for element type names, attribute names, notation names, enumerated values.
Option to preserve white-space in element content.
Handle SUBDOC entities by converting to NDATA with notation SGML. At least warn about them with -ondata.
Be able to preserve external entities. Provide a -oentity_name=file option that preserves references to entity_name and writes the normalized entity to file.