XML NEWBIE NOTE1

What is <!---->for?
It's XML Prolog.
prolog. The minimal prolog contains a declaration that identifies the document<!---->
The declaration may also contain additional information:
<!---->version: Identifies the version of the XML markup language used in the data. This attribute is not optional.
• encoding: Identifies the character set used to encode the data. ISO-8859-1 is Latin1, theWestern  European and English
   language character set.  (The default is 8-bit Unicode: UTF-8.)
• standalone: Tells whether or not this document references an external entity or an external data type specification. If there
   are no external references, then “yes” is appropriate.


It's optional to decalare this, actually, but keep is at least with simpliest way (only version attribute) is strongly recommended. 

until page96 of j2ee tutorial