Hi,

I'm not sure if this is the right place to report this, but I believe I've found something in the MODS to DC XSLT (MODS3-5_DC_XSLT1-
0.xsl) that could be fixed.

We were getting empty dc:subject elements in our XML from the following template:

<xsl:template match="mods:subject[mods:topic | mods:name | mods:occupation | mods:geographic | mods:hierarchicalGeographic | 
mods:cartographics | mods:temporal] ">
  <dc:subject>
    <xsl:for-each select="mods:topic | mods:occupation">
      <xsl:value-of select="."/>
      <xsl:if test="position()!=last()">--</xsl:if>
    </xsl:for-each>
    <xsl:for-each select="mods:name">
      <xsl:call-template name="name"/>
    </xsl:for-each>
  </dc:subject>

This was from MODS records that had mods:geographic elements, for instance, but no mods:topic, mods:occupation, or mods:name elements.  
My solution was to wrap the dc:subject that is generated for mods:topic or mods:occupation elements, and mods:name elements, in an xsl:test 
to make sure one of those exists before outputting the dc:subject element:

<xsl:if test="mods:topic | mods:occupation | mods:name">
  <dc:subject>
    <xsl:for-each select="mods:topic | mods:occupation">
      <xsl:value-of select="."/>
      <xsl:if test="position()!=last()">--</xsl:if>
    </xsl:for-each>
    <xsl:for-each select="mods:name">
      <xsl:call-template name="name"/>
    </xsl:for-each>
  </dc:subject>
</xsl:if>

I've attached a patch as well (which may more clearly illustrate the change).  If there is some place else (a GitHub repository, for 
instance) to which I should report this, please let me know.

Thanks,
Kevin