The group name is used in the namelist-directed I/O statement to identify the list of variables or arrays that are to be read or written. This name is used by namelist-directed I/O statements instead of an input/output list. The group name must be unique, and identifies a list whose items can be read or written.
A group of variables can be defined through several NAMELIST statements with the same group name. Together, these definitions are taken as defining one NAMELIST group.