Pull request submitted that changes "/" to "_": https://github.com/theforeman/foreman/pull/1006

And here's the fix to delete the broken bookmark:
[root@gatebuilder ~]# su - postgres
-bash-4.1$ psql
psql (8.4.18)
Type "help" for help.

postgres=# \c foreman
psql (8.4.18)
You are now connected to database "foreman".
foreman=# delete from bookmarks where name = '<incorrect/name>';

Ah ok, never mind then :-) Didn't see that bug.

No worries, thanks for the PR anyway! That bug covers a number of related issues, hopefully improving all of our resource identifiers to prevent these problems.