Displaying square brackets used in C programs
The standard non-APL terminals that ISPF supports do not have the left and right brackets used in a C program. Therefore, the translation tables provided with ISPF are defined so that these characters are not valid and are displayed as periods.
If you have a terminal that supports these characters, you can modify the translation tables TTVAL and TTGSM. To do so, simply indicate that these characters are valid.
Note that the C/370 compiler expects the brackets at code points AD and BD. On an APL or TEXT terminal, if you use the ISPF-supplied terminal type 3278A, the code points AD and BD are displayed correctly as left and right brackets.