Plain English Meaning
A sign that tells a pilot taxiing off the runway when they are far enough away from the runway to be considered clear of it.
Full Definition
An airport sign with a yellow background and black graphic showing the runway safety area/obstacle free zone marking, posted on the back of a runway holding position sign and used by pilots exiting the runway to identify the point at which they have cleared the runway safety area.
Context Anchor
Seen while taxiing off a runway, usually near the pavement marking that shows the runway holding position from the runway side.
Why Pilots Care
Until the aircraft passes this sign, it is still considered to be on the runway from a standpoint. Stopping short of it can block following or interfere with another aircraft's or . Knowing exactly where '' begins prevents and miscommunication with .