*  [https://sqlite.org/src/ext/checklist/env]

In addition to the standard CGI environment variables listed above, 
Fossil adds the following:

  *  FOSSIL_CAPABILITIES
  *  FOSSIL_REPOSITORY
  *  FOSSIL_URI
  *  FOSSIL_USER

The FOSSIL_USER string is the name of the logged-in user.  This variable
is missing or is an empty string if the user is not logged in.  The
FOSSIL_CAPABILITIES string is a list of 
[/setup_ulist_notes|Fossil capability letters] that
indicate what permissions the user has on the Fossil repository.
The FOSSIL_REPOSITORY environment variable gives the filename of the
Fossil repository that is running.
Fossil repository that is running.  The FOSSIL_URI variable shows the
prefix of the REQUEST_URI that is the Fossil CGI script, or is an
empty string if Fossil is being run by some method other than CGI.

The [https://sqlite.org/src/ext/checklist|checklist application] uses the
FOSSIL_USER environment variable to determine the name of the user and
the FOSSIL_CAPABILITIES variable to determine if the user is allowed to
mark off changes to the checklist.  Only users with check-in permission
to the Fossil repository are allowed to mark off checklist items.  That
means that the FOSSIL_CAPABILITIES string must contain the letter "i".