XML tagname starting with number is not working

An XML element whose name starts with a number is illegal XML. You should not start with numbers.

XML elements must follow these naming rules:

• Names can contain letters, numbers, and other characters
• Names cannot start with a number or punctuation character
• Names cannot start with the letters xml (or XML, or Xml, etc)
• Names cannot contain spaces

Any name can be used, no words are reserved.

http://www.w3schools.com/xml/xml_elements.asp

Specification Details.