lib/onix/normaliser.rb
def to_reference_tags(src, dest)
      inpath = File.expand_path(src)
      outpath = File.expand_path(dest)
      xsltpath = File.dirname(__FILE__) + "/../../support/switch-onix-2.1-short-to-reference.xsl"
      `xsltproc -o #{outpath} #{xsltpath} #{inpath}`
    end
def to_reference_tags(src, dest)
      inpath = File.expand_path(src)
      outpath = File.expand_path(dest)
      xsltpath = File.dirname(__FILE__) + "/../../support/switch-onix-2.1-short-to-reference.xsl"
      `xsltproc -o #{outpath} #{xsltpath} #{inpath}`
    end
uses an XSLT stylesheet provided by edituer to convert
 a file from short tags to long tags.

 more detail here:
   http://www.editeur.org/files/ONIX%203/ONIX%20tagname%20converter%20v2.htm