Where can a scaffolder find the unsupported maximum span length of a timber scaffold plank?

The unsupported maximum span length of a timber scaffold plank is indeed marked directly on the plank itself. This notation serves as an important safety guideline to ensure that the plank is used within its specified limits. By providing this information directly on the plank, it allows the scaffolder and any other users to quickly assess the safety of the setup without needing to refer to external documentation.

Marking this information on the plank is crucial for ensuring compliance with safety standards and ensuring that the scaffold is safe for use. This also helps prevent misinterpretation of the maximum span by providing a visible reminder of the safety limits that need to be adhered to during assembly and use of the scaffold. The other options, while they might contain useful information related to scaffolding, do not provide direct access to the unsupported maximum span length as clearly as that marked on the plank itself.