"Disciplinary probation" is the term many schools use to indicate that students -- or, sometimes, student organizations -- have engaged in behavior that the institution deems unacceptable. In contrast to being suspended or asked to leave an institution, disciplinary probation often lets students or student organizations remain at the school during a probationary period.
Disciplinary probation often requires students to remain free from any kind of disciplinary trouble during a predetermined time period. For example, a student who has gotten in trouble in the residence hall and who is placed on disciplinary probation must not have any other disciplinary problems in the hall. Probationary periods can be anything from a few weeks to an entire semester or academic year.
If you've been placed on disciplinary probation, it's important to be very clear on 1) what caused your probation, 2) how long your probation will last for, 3) what you need to do to get off of probation, and 4) what happens if you break your probation rules. Additionally, it's important to make sure you find positive support systems and keep yourself away from situations that might, even by chance, lead you to a probation violation.