That's becoming standard. Any activities that considered "high risk" are listed on the board so that all trades are aware of them. Also covers the GC, so that they can say that they are in fact tracking all high risk activities on site and have a point person responsible for each. So if the sub fails to identify their activity as high risk the sub takes the liability, and if the sub identifies the work as high risk the sub takes the liability since they were aware they were carrying out a high risk activity and should have prepared accordingly. But because of how safety is treated nearly every activity is considered high risk.
Working at heights? High risk. Hoisting and rigging? High risk. Traffic control? High risk. Hot work? High risk. Energized systems? High risk. Any kind of heavy equipment? High risk.
