The "repolist-skin" setting:

If non-zero then use this repository as the skin for a repository list
such as created by the one of:

   1)  fossil server DIRECTORY --repolist
   2)  fossil ui DIRECTORY --repolist
   3)  fossil http DIRECTORY --repolist
   4)  (The "repolist" option in a CGI script)
   5)  fossil all ui
   6)  fossil all server

All repositories are searched (in lexicographical order) and the first
repository with a non-zero "repolist-skin" value is used as the skin
for the repository list page.  If none of the repositories on the list
have a non-zero "repolist-skin" setting then the repository list is
displayed using unadorned HTML ("skinless").

If repolist-skin has a value of 2, then the repository is omitted from
the list in use cases 1 through 4, but not for 5 and 6.