10.1.5 Jade

Jade is used for validating tbook documents without converting them (e.g. Emacs calls Jade to test whether the syntax of the current tbook buffer is valid). It is also used to convert DocBook documents, which means that is converts tbook to RTF for example.

1. Jade reads an invalid declaration file. All SGML implementations rely on an erroneous xml.decl file. See Jade/nsgmls issues, for how to fix this.
2. Jade complains about invalid xmlns:... attributes. Jade isn't aware of XML's namespace conventions. You can ignore these messages completely.
3. Jade complains about invalid MathML elements. The standard DocBook XML DTD doesn't contain MathML, so this is only natural. Since there is no DocBook tool known to me that can actually process MathML anyway, I consider this a somebody else's problem, too.