Soft verges for 2 miles' Supplementary Plate - Post Mount Dia. 556.2 R2/RA2This supplementary plate is part of our permanent road sign range and serves to warn drivers of soft verges. Soft verges may not only cause a vehicle to get stuck, but can also damage the vehicle, and cause significant damage to the verge itself. This supplementary plate should only be used with sign diagram 556. 1. This sign can be varied to change the distance the warning applies for. The distance can be completely omitted as can the word for. For