The traffic sign you mentioned is "Note by verbal indication" (sign 1012-51). This sign is used to indicate that a verbal message or instruction is being communicated, usually by authorized personnel, to road users. It is commonly seen in contexts where traffic direction or safety instructions are provided verbally, such as at construction sites or during special events.

Drivers should pay extra attention when they see this sign, as it indicates that they may need to follow instructions given by a person, which might supersede regular traffic rules. Always be prepared to comply with verbal directions as they are important for safety and traffic management.

If you have any further questions about this or any other traffic rules, feel free to ask!