I researched the official names of SYN and ACK during TCP 3-way handshake, so here’s a memo.

The non-abbreviated names of SYN and ACK in TCP 3-way handshake.

SYN: synchronize (synchronization signal?) ACK: acknowledge (positive response)

RFC 793 TRANSMISSION CONTROL PROTOCOL

■ Connection Flow with 3-way Handshake

Client sends SYN to server. Server returns SYN + ACK to client. Client sends ACK to server. This establishes the TCP connection.

・Source: Official Names of SYN ACK in TCP 3-Way Handshake

【Reference】

・3-Way Handshake - Wikipedia

That’s all from the Gemba.