In some aspects, methods and apparatus for wireless communications are configured to generate a packet for wireless communication where the packet includes a mark symbol in a preamble of the packet where the mark symbol includes a signature or stamp field in the mark to provide protocol information that indicates the protocol of the packet, such as an 802.11 EHT packet. In some other aspects, a cyclic redundancy check field in the mark symbol may be manipulated in various ways to indicate the protocol of the packet in lieu of providing the signature or stamp field.