The tcpdump man page appears not to document one of the TCP flags

[aes256ctr]

https://www.tcpdump.org/manpages/tcpdump.1.html

|  HL   | rsvd  |C|E|U|A|P|R|S|F|        window size            |

I think there is a missing TCP flag：Accurate ECN

[infrastation]

Thank you for bringing this up, let's treat this as a duplicate of #999.

[guyharris]

Duplicate of #999