Server Configuration > Server Policies for SCM > Locks Policies > Locking Revisions in Multiple Development Paths
  
Locking Revisions in Multiple Development Paths
For both the advisory and exclusive locking models, users can have one lock per archive per development path. This enables users to have multiple locks on the same revision when required, for example, in situations where users are:
working on both the main branch of development (where new development is occurring) and in a variant Sandbox (where fixes are occurring)
working in two variant Sandboxes and need to modify a different revision in the same member history in each Sandbox
sharing the member history across many projects and need to modify a different revision in the same member history in each particular project