RelaxNG Schema for XML-compliant HTML

HTML

Generic HTML is made up of one or more html_paragraphs.

html_text = text* &
            element u { html_text }* &
            element strong { html_text }* &
            element em { html_text }* &
            element sub { html_text }* &
            element sup { html_text }* &
            element cite { html_text }* &
            element mark { html_text }* &
            element s { html_text }* &
            element small { html_text }* &
            element q { html_text }* &
            element wbr { empty }* &
            element a { html_text,
                         attribute href { text },
                         attribute title { text }?
                      }*

html_paragraphs = element p { html_text }* &
                  element h4 { html_text }* &
                  element h5 { html_text }* &
                  element h6 { html_text }* &
                  element hr { empty }* &
                  element pre { html_text }* &
                  element blockquote { element p { html_text }* &
                                       element pre { html_text }* &
                                       element ul { element li { html_text }* }* &
                                       element ol { element li { html_text }* }*
                                      }* &
                  element ul { element li { html_text }* }* &
                  element ol { element li { html_text }* }*

HTML for Content

HTML for content is also made up of one or more html_paragraphs. The definition for html_paragraphs however includes the additional slot tag which can be used to place media inside the content using a tag like this:

<slot id="{SLOT_UUID}" />

uuid = xsd:string { pattern = "[a-fA-F0-9]{8}-[a-fA-F0-9]{4}-[a-fA-F0-9]{4}-[a-fA-F0-9]{4}-[a-fA-F0-9]{12}" }

html_text = text* &
            element u { html_text }* &
            element strong { html_text }* &
            element em { html_text }* &
            element sub { html_text }* &
            element sup { html_text }* &
            element cite { html_text }* &
            element mark { html_text }* &
            element s { html_text }* &
            element small { html_text }* &
            element q { html_text }* &
            element wbr { empty }* &
            element a { html_text,
                         attribute href { text },
                         attribute title { text }?
                      }*

html_paragraphs = element p { html_text }* &
                  element h4 { html_text }* &
                  element h5 { html_text }* &
                  element h6 { html_text }* &
                  element hr { empty }* &
                  element pre { html_text }* &
                  element blockquote { element p { html_text }* &
                                       element pre { html_text }* &
                                       element ul { element li { html_text }* }* &
                                       element ol { element li { html_text }* }*
                                      }* &
                    element ul { element li { html_text }* }* &
                    element ol { element li { html_text }* }* &
                  element slot { attribute id { uuid } }*