The longest command string that you can pass to DCL before symbol substitution is 255 bytes for V7.3-1 and earlier, 4095 bytes for V7.3-2 and later.
The longest string that SHOW SYMBOL can display without an informational message (%DCL-I-SYMTRUNC, preceding symbol value has been truncated) is 500 bytes for V7.3-1 and earlier, 4087 bytes for V7.3-2 and later. This appears to be an output buffer size limitation.
The longest string that can be manipulated using lexical functions, concatenation or reduction is 510 bytes for V7.3-1 and earlier, 8173 bytes for V7.3-2 and later.
