Temporary restrictions are sometimes called 'deferrals', since blood donors who are found ineligible may be found eligible at a later date. Many countries have laws, regulations, or recommendations that effectively prohibit donations of blood or tissue for organ and corneal transplants from men who have sex with men (MSM), a classification of males who engage or have engaged in sex with other males, irrespective of their sexual activities with same-sex partners and of whether they identify themselves as bisexual or gay.
