> The errata-corrected versions can be expected to change as more errata
> are discovered. files.scheme.org should have some way to distinguish
> between set-in-stone files (like a git tag) and moving targets (like a
> git branch).

A simple proposal: all moving-target files have "-latest" appended to
their names, and are symbolic links to set-in-stone files.

For example, errata-corrected-r6rs-latest.pdf could be a symbolic link
to errata-corrected-r6rs-2020-08-30.pdf. The latter could also be
downloaded directly and would be kept in the archive in perpetuity.