18.104.22.168.2 STFU (1.30.14)
When this bit is set to a one, the PMA/PMD sends a message to the link partner instructing it to be silent for
the silence time (see 22.214.171.124.3).
To translate that into english, there is a bit called "STFU" which informs the other end of the link to cease transmission ("stop talking"). For those not up-to-speed on their instant messaging/texting shorthand, "STFU" is short for "Shut The F*** Up".
I'm sure someone had a laugh when they snuck this one into the spec.