The standard defines the for verifying whether a workpiece or measuring equipment conforms to a given specification. It introduces the concept of the "Uncertainty Interval" around the tolerance limits. Without this rule, a manufacturer might scrap perfectly usable parts (producer's risk) or accept defective parts (consumer's risk).
: LSL = 19.95, USL = 20.05.
Does your current inspection process account for measurement uncertainty per ISO 14253-1, or do you still use simple "within limit = good" logic?