The WWP encodes all back matter, and places it within a <back> element. This may include indexes, errata lists, colophons, epilogues, endnotes, appendices, advertisements, as well as unforeseen things which by their nature cannot be predicted here. Most of these things are encoded with <div>, using the following <div> types:
concluding (replaces the old values appendix and backpart)
The “concluding” value is analogous to the “prefatory” value for front matter; it covers any prose division in the back matter not covered by the other back matter values listed here: appendices,
A colophon is usually a slightly shorter version of the <docImprint>, and is often the very last piece of text in the entire document. The WWP encodes colophons as <titleBlock type="colophon">, since these are often the equivalent of the title page in a modern book.
Epilogues to plays or novels, where such an epilogue was written to be performed with the play, or to be read with the novel, rather than to introduce a particular edition, should be encoded using <div type="epilogue"> as part of the <body> element, unless some other indisputably <back>-like element intervenes. Note that epilogues may occasionally be printed at the start of a play. In this case they should be encoded where they appear, within <front> or <body> depending on their content.