Last updated: 13 Oct 2019.
Complete history since some time in 2018 (before I properly somewhat 'standardised' my date format - at different times I have used different formats, quite foolishly) can be found here.

Document history (since 2018/05/12)

For a list of changes in each subdomain please see the index page for each of the subdomains; I try to keep all the indices updated but it's entirely possible this won't remain true by accident (and sometimes because it seems insignificant or I simply cannot be bothered though this is rather unusual).