• etc - contains configuration files
• log - contains mail and command logs, and the repository parent pointer.
• deleted - deleted files are archived here (similar to the CVS ``Attic'').
• tmp - scratch area.
• readers - Transient directory for reader locks.
• writer - Transient directory for writer lock.
• triggers - Executable trigger programs are stored here.

In addition to the directories that get created, there are a number of files associated with each file kept under revision control, as follows:

• foo.c - your source file (the gfile, or ``gotten'' file).
• SCCS/s.foo.c - the revision history of all versions of the gfile, known as the ``s.file''.
• SCCS/p.foo.c - the lock file, created when the file is edited, known as the ``p.file''.
• SCCS/z.foo.c - a lock file created when locking or checking in a new version, known as the ``z.file''.
• SCCS/x.foo.c - a temporary file containing the new version of the s.file under construction. When the checkin is finished, the s.file is removed and this ``x.file'' is moved in its place.
• SCCS/b.foo.c - a temporary backup of local s.file while resolve is applying new files. If all goes well, these files, the ``b.files'', are removed, but if the application fails, the b.files are moved back in place.
• SCCS/c.foo.c - a temporary copy of check-in comments, currently used only by bk citool.