If I have read the specs correctly, a <tee-set> can contain a <summary>, and within that <summary> are tags: <front><back><holes< and <par>
Like this:
<tee-set>
<summary>
<front units="meters">3027</front>
<front units="yards">3311</front>
<back units="meters">2844</back>
<back units="yards">3109</back>
<holes>18</holes>
<par>71</par>
</summary>
</tee-set>
If that is so, then the <holes> and <par> tags are in the wrong scope. They are a property of the <golf-course> rather than the <tee-set>, since all <tee-set>s within a <golf-course> will have the same Course Par and the same number of holes.
Have I missed something when reading the spec?