The parameters passed in a call by context are protected from modification by the called program. In a normal call they are able to be modified.
Partial list: REMARKS, NOMINAL KEY, PAGE-COUNTER, CURRENT-DAY, TIME-OF-DAY, STATE, FLOW, COUNT, EXAMINE, EXHIBIT, READY TRACE and RESET TRACE.
Before IBM introduced MVS/XA architecture in the 1980’s a program’s virtual storage was limited to 16 Megs. Programs compiled with a 24 bit mode can only address 16 Mb of space, as though they were kept under an imaginary storage line. With COBOL II a program compiled with a 31 bit mode can be ‘above the 16 Mb line. (This ‘below the line’, ‘above the line’ imagery confuses most mainframe programmers, who tend to be a literal minded group.)
NEXT SENTENCE gives control to the verb following the next period. CONTINUE gives control to the next verb after the explicit scope terminator. (This is not one of COBOL II’s finer implementations). It is safest to use CONTINUE rather than NEXT SENTENCE in COBOL II.
The PERFORM and END-PERFORM statements bracket all COBOL II statements between them. The COBOL equivalent is to PERFORM or PERFORM THRU a paragraph. In line PERFORMs work as long as there are no internal GO TOs, not even to an exit. The in line PERFORM for readability should not exceed a page length - often it will reference other PERFORM paragraphs.