Optional Post @{visual-Meta Appendices

The following optional Visual-Meta appendices are added after the main, required Visual-Meta appendix, and can therefore be removed or appended again and again, easily without interfering with the required Visual-Meta.
This means that errata can be attached without amending the original document and that annotations and VR/AR position data can travel with the document.

Mechanics for the issuing of errata pages. 

Mechanics for presenting reader annotations in an easily accessed format. 

Mechanics for recording VR/AR/Metaverse positions of elements in the document on closing the document. Contains a simple data structure exported by the VR environment to be accessed when next entering that location, and then wiped, for a new entry to be appended on next exit.

Mechanics for recording who has read the document. @{visual-meta-usage-end}