Sign for stopping clear?

[krausyao]

In section 6.8 of the General Code of Operating Rules - Fourth Edition - April 2, 2000 is a diagram showing that trains need to stop at least 400ft (122m) from the signal. Is there a sign on the track to let the engineer know where this point is and what does this sign look like?

6.8 Stopping Clear for Meeting or Passing
A train that may be met or passed must stop at least 400 feet from the signal or clearance point of the facing point switch the other train will pass over, if length of train permits.

[jovet]

I've never seen such a sign, but sometimes the tracks are marked or painted to indicate the limits of circuits and safe stopping distances.