Apologies if this question is too easy or if I have not read the schema documentation enough.<br>
<br>
My schema is like this: There will be a choice between one of the two groups a and b. <br>
 
<p>... <br> &nbsp; &nbsp; &nbsp; &nbsp; &lt;xs:choice&gt; <br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &lt;xs:group ref=&quot;a&quot;/&gt; <br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &lt;xs:group ref=&quot;b&quot;/&gt; <br> &nbsp; &nbsp; &nbsp; &nbsp; &lt;/xs:choice&gt;&nbsp; <br>
... <br> </p>
<p>however if I have the following group declaration it will not pass. The error message will say that &quot;X&quot; cannot appear in both groups. <br> </p>
<p>&nbsp; ... <br> &nbsp; &nbsp; &nbsp; &nbsp; &lt;xs:group name=&quot;a&quot;&gt; <br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &lt;xs:sequence&gt; <br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &lt;xs:element ref=&quot;X&quot;/&gt; <br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &lt;xs:element ref=&quot;Y&quot;/&gt; 
<br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &lt;/xs:sequence&gt; <br> &nbsp; &nbsp; &nbsp; &nbsp; &lt;/xs:group&gt; <br> &nbsp; &nbsp; &nbsp; &nbsp; &lt;xs:group name=&quot;b&quot;&gt; <br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &lt;xs:sequence&gt; <br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &lt;xs:element ref=&quot;X&quot;/&gt; 
<br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &lt;xs:element ref=&quot;Z&quot;/&gt; <br> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &lt;/xs:sequence&gt; <br> &nbsp; &nbsp; &nbsp; &nbsp; &lt;/xs:group&gt; <br> &nbsp; ... <br> &nbsp; ... <br> </p>
<p>The strange thing is that if I have the following combination it will <br> not work: <br>   XY XY <br>   XY XX <br> </p>
<p>However the following will work: <br>   XY YX <br>   XX YX <br>   XY YY <br> </p>
<p>This means that it will only fail if the first element of both group
is the same. Anything else will pass. This seemed really strange <br> to a newbie like me. Is there anyway around it? By the way I am using the validator from here:<br>
<a href="http://tools.decisionsoft.com/schemaValidate.html">http://tools.decisionsoft.com/schemaValidate.html</a><br> </p>
Cheers <br>
 Mark