Specifies a bit mask indicating alternative handling for control characters.

The mask is represented in 32 bits or 8 hexadecimal digits, with 1 bit for each of the first 32 ASCII characters. To activate alternative handling for a character, set the bit corresponding to the power of 2 equal to the character's ASCII code.

GT.M currently provides alternate handling only for <CTRL-U>. A mask of 00200000 enables <CTRL-U> processing. With alternative <CTRL-U> handling, a <CTRL-U> in the input causes the cursor to go back only through the current field, not to the beginning of the line.