with a form or protection, or allowing work to be done behind a passing train. Comparison with Direct Traffic Control Track Warrant Control is similar to yet distinct from the concept of Direct Traffic Control (DTC), appearing later as railroads migrated fully from older forms of Train order operation. DTC was designed to facilitate the movement of trains using concepts of blocks and sidings previously used with Train Orders. DTC is only a mechanism to transfer movement authority and can only work within an arrangement of predefined blocks. Track Warrant systems appropriate the remaining responsibility of Train Order systems to notify operating personnel of safety directives that include things like temporary speed restrictions, tracks out of service, etc. and combines them with the movement authority function of DTC. Furthermore, Track Warrants are not limited to fixed blocks and can be issued and released from almost any explicitly identified landmark along the rail line. Standard instructions used in track warrants Most track warrants in the U.S. follow a standard form as suggested by the General Code of Operating Rules, consisting of several standard instructions to mark specific notes or conditions for a warrant. These vary from temporary speed restrictions to rules regarding meeting other trains. Box 1. Void on a previous warrant. Box 2. Proceed from point to point. Box 3. Proceed from point to point (cont.) Box 4. Work between certain limits. Box 5. Not in effect until . Box 6. Authority expires at . Box 7. Not in effect until after the arrival of at . Box 8. Hold main track at last named point. Box 9. Do not foul limits ahead of . Box 10. Clear main track at last named point. Box 11. Between and make all movements at restricted speed: limits occupied by train. Box 12. Between and make all movements at restricted speed: limits occupied by men or equipment. Box 13. Do not exceed mph between _ and . Box 14. Do not exceed mph between _ and . Box 15. Flag protection not required against following trains on same track. Box 16. Track bulletins in effect. Boxes 17 and 18: Other specific instructions. Some railroad systems, such as RailAmerica, use additional boxes: Box 18. Joint with _ between and _ . Box 19. Expect to find the following switch(es) lined and locked in the reverse position: _ . Box 20. The following switch(es) may