Reply, response, or commentary concerning the journal article. In the typical case, the response is included in the same XML package as the original article, attached at the end of the article proper. Metadata that differs from that of the original article (for example, title, author), may be captured using the <front-stub> element; if the <front-stub> element is used, any metadata not specifically tagged is inherited from the original article.
The following, in order:
Any one of:
<body> Body of the Document, zero or one
<back> Back Matter, zero or one
<floats-group> Floating Element Group, zero or one