Hook

• Rick Jelliffe's Hook: A One-Element Language for Validation of XML Documents based on Partial Order

• XSLT/XPath based

• No data typing; validation only

• A Hook schema for XHTML (adapted from Rick Jelliffe):

  <hook:order targetNamespace="http://www.w3.org/1999/xhtml" >
    html head  [ title; meta. link. base. ]   body
    [ a br. blockquote caption; div  dl; h1; h2; h3; h4; h5; h6;  
      img. ol; p; pre; table; ul; ]  
    [ tr;  dt; dd; li; ]  td 
    [ a br. blockquote div  form img. ol; ul; li; ]  
    [ input; label; select; textarea; ]  [ option. ]
    [ abbr acronym address cite code dfn em kbd q samp span strong var object; ] 
    param 
  </hook:order>
  

• http://www.ascc.net/xml/hook/