This field is used to specify a set of values which the parameter may take. IN can only be specified for parameters of standard primitive type other than _LOGICAL, and is only relevant if the parameter value is a scalar.
A parameter cannot have both a RANGE and an IN field and IN cannot be specified before TYPE has been declared.
Checking is carried out when a program attempts to get the value of a parameter.
No checking occurs when putting a value. For _CHAR parameters the check is case independent.
If the constraints are violated, the system reports the error and prompts for another value unless the parameter had VPATH INTERNAL, in which case status SUBPAR__OUTRANGE is returned.
The field is of the form:
where set-of-values consists of a list of character or number constants specifying the valid values for the parameter. The specified values must all be convertible to the type of the parameter. The set of values is terminated by the next reserved-word token, therefore any required string which corresponds with a reserved word must be enclosed in quotes.IN set-of-values
ADAM Interface Module Reference Manual