When two files are matched up, the way that they are combined is defined by an extra attribute that is specified in file 2 called xml-combine. This attribute is used only to specify how the files are combined, and is removed before the resulting file is generated. The xml-combine attribute can have the following values:
- xml-combine="replace"
 - xml-combine="remove"
 - xml-combine="append"
 - xml-combine="append-without-matching"
 - xml-combine="prepend"
 - xml-combine="prepend-without-matching"