Others indicate which device or file your process uses for input and output. Some commonly used predefined logical names are listed in Table 1 . TT is the default name assigned to your terminal. Symbols A symbol may substitute for either a character string or an integer value. Symbols may be used as counters in command procedures or used as substitutions for commonly executed commands.
Some commands use symbols to refer to data records.
Two types of symbols may be created. You create symbols with DCL assignment statements.