value: A number, series of characters, or truth-value that conforms to the definition of a type.
value passing: The process of obtaining a value for a g2-to-g2-variable from a remote G2 process through the use of an external interface.
variable failure: The result of an attempt to obtain a new current value for a variable, where the variable does not receive a value within its specified time-out period. The variable can also fail to obtain a new current value after G2 has used all appropriate means to obtain the value and has failed to do so.