Standings & Promotions is a Committee of the Faculty that handles exceptions to academic policies. Generally these exceptions are due to issues beyond your control.
In order to petition, you need to have a petitionable problem, generally an issue (i.e. death of relative) not common to other students. A typical example of a problem that is not petitionable is - acclimatizing to the university. Every student in the Faculty undergoes this transition, so it is considered to be "common". Secondly, you need proof.
Proof is a definite must. It can include such things as death certificates, medical notes, etc. Your academic advisor will help you identify the kind proof that is required.