title: xml tag can consists of integer values or can contains special characters?
body: <p>For example.
  Are these xml tags acceptable or not.</p>
  
  <pre><code>&lt;xml&gt;
  &lt;3333&gt;abc&lt;/3333&gt;
  &lt;ab#$3&gt;def&lt;/ab#$3&gt;
  &lt;/xml&gt;
  </code></pre>
  
  <p>My question is can I create tags of integers values or a tag with Special characters ?</p>
  
  <p>I tried this  </p>
  
  <pre><code>FileStream fs = new FileStream((filename), FileMode.Append);
  XmlWriter w = XmlWriter.Create(fs);
  w.WriteStartElement("3454");
  </code></pre>
  
  <p>and got the following error
  <code>{System.ArgumentException: Invalid name character in '3454'. The '3' character, hexadecimal value 0x33, cannot be included in a name.
     at System.Xml.XmlWellFormedWriter.CheckNCName(String ncname)
     at System.Xml.XmlWellFormedWriter.WriteStartElement(String prefix, String localName, String ns)
     at System.Xml.XmlWriter.WriteStartElement(String localName)
     at WindowsFormsApplication1.Form1.fn_setMapping(SqlString keyString, SqlString column, SqlString value)</code></p>
  
  <p>Thank You</p>