This preference allows users to choose which projects' content will
appear in digests they receive.
By default, all projects are in the "Include" list. Server
administrators may elect to change the default "Include" list.
Note: Besides
changing this default listing, however, server administrators may also
choose to restrict which projects are eligible
to have their content appear in digests. Projects
that are disallowed at the server level will never be represented in any
digest. See
the Projects to Include in Digest topic for more information on that feature.