Effects of source control on object management
You must check out a target file from source control before
you can modify its properties. If objects in a source-controlled
target are not themselves registered in source control, you can add
them to or delete them from the local target without checking out
the target. However, you must remove a source-controlled object from
the source control system before you can delete the same object from
the local copy of the target (whether or not the target itself is
under source control).
Although you can add objects to a source-controlled target
without checking out the target from source control, you cannot add
existing libraries to the library list of a source-controlled target
unless the target is checked out.
For information on removing an object from source control, see
Removing objects from source
control.