Wrote some XSLT to do the following:

• Replace all instances of U+0027 in text() nodes with U+2019, following our editorial decision to that effect yesterday.
• Transform old oxygen processing instructions to xml-model PIs for the RNG schema.
• Add a PI pointing to the Schematron schema.

I've transformed all the documents with this, and validated them all. Flow has instructions for creating a Code Template in Oxygen to simplify typing of the U+2019 character. I've also added a constraint to the Schematron schema which enforces this.

The XSLT and Schematron were fiddly to get right because of the difficulties escaping the single-quote -- use-mention was hard to get around. For the record, these are the only approaches which seem to work (different for XSLT versus Schematron):

  <xsl:template match="text()">
    <xsl:value-of select="replace(., '''', '’')"/>
  </xsl:template>

    <rule context="text()">
      <assert test='not(contains(., "'"))'>
        "Straight apostrophe" characters are not permitted. Please use the 
        Right Single Quotation Mark (U+2019) character instead.
      </assert>
    </rule>