[dba-SQLServer] XML Q

Hello all
Cross Posted to dba_SQL List
What is the minimum header information ineed to include
before 'my data' starts
to get a 'Well formed' xml doc?
Eg the stuff that looks like
<?xml version="1.0"?><Report xmlns="Invoice2"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

 

etc etc

 

many thanks