# TCP header flags - URG - Process the current [[TCP]] packet immediately. Directs the receiving system to examine the "urgent pointer" field. - ACK - Acknowledgement. Directs the receiving system to examine the "acknowledgement number" field. - PSH - Push. Elevate the priority of the packet's data, but does not otherwise change rules around packet processing. - RST - Reset. Terminates the connection forcefully. - SYN - Synchronize. Used during the initial three-way handshake to set a shared (starting) sequence number. - FIN - Finish. Indicates that the connection may be dropped gracefully.