Explain MMC, LMC, and RFS material conditions and when to apply each?

MMC (Maximum Material Condition) is when a feature contains the most material (smallest hole, largest shaft), used when assembly clearance is critical and allows bonus tolerance as features depart from MMC. LMC (Least Material Condition) is when a feature has the least material, used to ensure minimum wall thickness. RFS (Regardless of Feature Size) applies the tolerance regardless of actual size, used when functional requirements demand consistent control at all sizes.