Category I can refer to: Category I New Testament manuscripts - Alexandrian Category-I Miniratna public sector undertakings (India) Category I measurement - performed on circuits not directly connected to MAINS Category I (a/b) protected areas (IUCN) - Strict Nature Reserve (Ia)/Wilderness Area (Ib)
See also Class I (disambiguation) - class/category equivalence (for labeling) Type 1 (disambiguation) - type/category equivalence (for labeling) Group 1 (disambiguation) - group/category equivalence (for labeling) Category 1 (disambiguation) - Roman/Arabic numbering equivalence