The SETB symbol in the name field can be subscripted. If the same SETB symbol has not been previously declared in a GBLB or LCLB instruction with an allowable dimension, and has not been implicitly declared in a SETB instruction as a scalar (unscripted)variable symbol, then the symbol is implicitly declared as a local SETB array variable.

The assembler assigns the binary value explicitly specified, or implicit in the logical expression present in the operand field, to the position in the declared array given by the value of the subscript. The subscript expression must not be 0 or have a negative value.