XML Companion, The, Third Edition

Recursive processing

Inclusions are processed recursively. When included text contains further inclusion instructions, these instructions are in turn detected and processed:

As mentioned above, a document may contain an include instruction that selects material from elsewhere in the same document (rather than from another document). This possibility raises a potential complication, because the material to be selected could itself contain an include instruction, and this instruction may or may not have already been processed:

Various XInclude processors ...