Basically, suppression rules are the opposite of indication rules; that is, depending on already given answers, they define that certain further question/questionnaires are not presented to the user. Furthermore it is also possible to suppress certain answer alternatives.
A. Suppression of questions/questionnaires#
IF Year of construction < 1995 THEN NOT [Does your car have ABS?]
In the example, the question Does your car have ABS? is suppressed (not shown to the user) if the question Year of construction was answered with a valua smaller than 1995.
B. Suppression of answer alternatives#
IF Engine start = does not start THEN HIDE "Battery o.k.?" = [yes]
Here, the answer alternative yes for the question Battery o.k.? is suppressed if Engine start was previously answered with does not start.
Note: in all cases it is important that the question/answer alternative, that is to be supressed, is defined in a different questionnaire as the initiating question; otherwise the supression mechanism does not work correctly. Multiple questions/questionnaires can be specified within square brackets, separated with semicolons.