The "VMC" patch on a biker's vest typically stands for "Veterans Motorcycle Club." Motorcycle clubs with the "VMC" patch often consist of veterans of the armed forces who share a common interest in motorcycles and camaraderie. These clubs are often involved in community service, charitable events, and support for veterans. However, it's worth noting that the meaning of patches can vary among different clubs, and it's always best to confirm with the specific club or individual wearing the patch to understand its exact significance in their context.