In1972,Fullerprovedthatacompleteadditivesubeategory_RCofR-Modisequivalenttoamodulecategory⊿-Modifandonlyif_RC=Gen(_RU)forsomequasiprogenerator_RUand⊿≌End_RUcanonically.Inthisnotetheauthorgivesacharacterizationof_RCwhichmakes_RUaprojectiveR-moduleinthecasewhenRisarightperfectringwithidentity,andshowsthatR-ModistheuniquecompleteadditivesubcategoryofR-ModwhichisequivalenttoR-ModforaleftArtinianringR.
