Support for editing legacy SGML

[B_Back]

Is there any plugin/addon that supports the editing and validating of legacy SGML files (and DTDs)?
i.e. DTDs like this one here:

Code: Select all

<!ELEMENT mail - - (head,body)>
<!ELEMENT head - O ((to & fr) & sb?)>
<!ELEMENT body - O (#PCDATA)>
<!ELEMENT to - O (#PCDATA)>
<!ELEMENT fr - O (#PCDATA)>
<!ELEMENT sb - O (#PCDATA)>

[Radu]

Hi,

Oxygen supports the XML specification and the DTD specification defined in the XML specification.
So we have no SGML support.

Regards,
Radu