Hi,

It is possible to add any status you like : menu Parameters => List of Values => Status

Then you can add this status in any workflow : menu Parameter => List of Values => Workflow
(change an existing one or design your own)

On a workflow you can define which profile can change from a satus to another.
For instance, for a "Waiting" status, you can define that only a Project Leader can move to it, and an external team member can quit it to a new status.

Then update the type of item you want for using the workflow : Parameters => List of Values => Type of ...
You select a workflow for each type, and every item of this type will respect the workflow.

Regards.

Babynus.