A caveat! A PL/I structure assingment is not the same as a COBOL group move. A PL/I structure assignment is equivalent to an assignment of the individual fields.
For example, MOVE "A" TO GROUP-X results in GROUP-X containing an "A" in the first byte and spaces in all the other bytes, regardless of the definition of the elementary fields withing GROUP-X.
In PL/I, STRUCTURE-X = "A" results in each elementary field within STRUCTURE-X containing an "A" followed by spaces. Also, the compiler should mark this statement as an error if any of the elementary fields are not alphameric.