S-800
Distance to start of danger or regulation
Indicates the distance from the sign to the point where the danger begins or where the sign's regulation starts to apply. When placed below the road narrows danger sign, it may indicate the clear width of the narrowing.
Category: Signs for use in built-up areas
Source: General Traffic Regulations (RD 1428/2003), Annex I; designs per the official sign catalog (RD 465/2025)