What this sign mean

[Badhorse79]

I seen this sigh and wonder if its for MOW or something to do with track work?  

[Conductor]

That's a CSX warning board for a speed restriction or Rule 89 (MOW Work Limits).

[Badhorse79]

Thanks I seen this one time before around Walton ky and it was explained to me but I wasn't listening (sorry Mr.Hanks )

[T. Mahan]

Advance Warning sign, indicates either a temporary slow order or work limits (704/707) two miles in advance.  Also referred to as a 'firecracker' by some crews.