Banana Republic Malibu Tee (S/P) Fit

Banana Republic Malibu Tee Crew Neck - Magenta - Decal Tag says S/P but this t-shirt fits like a typical BR Medium t-shirt. I wear BR all the time. Washed and worn one time, no shrinkage. Fits between a Small and a Medium, the decal tag says S/P but I don't know what is Petite about it. I think it fits like a BR typical Medium fit. See picture of tag decal 55% Cotton/45% Modal - the Cotton is not softer than a typical 100% Cotton BR t-shirt, great quality material