LISD

When a lady is wearing short-shorts, a lady's jacket should either be considerably longer or considerably shorter so as to avoid seeming to suggest that said lady is wearing nothing underneath said jacket.

However, in the event that a lady finds herself wearing short-shorts and her sole rain jacket, and in the event that it is raining, she must follow the Least Inseam Scandal Deflector (LISD). Very simply, the LISD is the inseam of the shortest shorts that could be worn with a given jacket without causing scandal. For all cases, the inseam must extend at least to the bottom of the jacket's back hem, as the movement from walking will cause the jacket to occasionally slip upward, exposing the bottom hem of the shorts, thereby expelling any suspicions that the lady may be unclad underneath.