It's hard to find thing on google unless you take the trouble to learn the terminology. userID and batchID are attributes. The thing from "<batch" to ">" is called a start tag; it marks the start of an element. People often use the word "tag" incorrectly to mean "element"; you are using it incorrectly to mean "attribute". With that kind of confusion, google doesn't stand a chance.
Wrox do some excellent books...
Author, XSLT Programmer's Reference and XPath 2.0 Programmer's Reference