What does load/span class mean?

Load/span class states how much uniformly distributed load a ladder can carry over a defined support span. For example, NEMA-style classes relate load rating to spans such as 8 ft, 12 ft, 16 ft, or 20 ft, while harmonized standards also include metric spans such as 3 m and 6 m. Buyers should always check the manufacturer’s tested safe working load table instead of selecting by appearance only.