Note 1 to entry: The absence of necessary external resources may prevent operation, but do not affect the up state. See externally disabled state (192-02-23).

Note 2 to entry: Up state relates to the availability of the item.

Note 3 to entry: An item may be considered to be in an up state for some functions and in a down state for others, concurrently.

Note 4 to entry: The adjectives "up" and “available” designate an item in an up state.