Man pages matching name tshttptxnserverpacketmarkset in section 3ts:

TSHttpTxnServerPacketMarkSet.3ts.en	debian 10 / trafficserver-dev
TSHttpTxnServerPacketMarkSet.3ts.en	debian 11 / trafficserver-dev
TSHttpTxnServerPacketMarkSet.3ts.en	debian 12 / trafficserver-dev