The state of a control in which normal functionality is not presently available to a user (also referred to as grayed, dimmed, and disabled).

not available or accessible or at hand; "fresh milk was unavailable during the emergency"; "his secretary said he was unavailable for comment"

this is a feature member's can enable in their Edit Settings screen in the User CP, which in effect disables the Online Indicator that is seen in posts and in profiles.

Not applicable in the current system state. When a component is unavailable, it appears dimmed and is skipped by keyboard navigation.

Edit / An agent state that indicates the agent is unavailable to take calls or make outgoing calls. It is generalized in that it does not convey information about why the agent is unavailable. See Also: Agent Agent Group Queue

The status of an agent who is logged in to the Automatic call distribution (ACD) system, but has blocked any incoming calls. The agent may be on a paid break or in a coaching session. (See available.)

an agent may make themselves unavailable for a next call, even though they have not logged off, to (eg) enter data etc.