group name can appear in only the NAMELIST, READ, or WRITE statements, and must be unique for the program.
list cannot include constants, array elements, dummy assumed-size arrays, structures, substrings, records, record fields, pointers, or pointer-based variables.
Example: A variable in two NAMELIST groups:
REAL ARRAY(4,4) CHARACTER*18 SAMPLE LOGICAL*4 NEW REAL*4 DELTA NAMELIST /CASE/ SAMPLE, NEW, DELTA NAMELIST /GRID/ ARRAY, DELTA
In the above example, DELTA is in the group CASE and in the group GRID.