Many countries have laws, regulations, or recommendations that effectively prohibit donations of blood or tissue for organ 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. Temporary restrictions are sometimes called "deferrals", since blood donors who are found ineligible may be found eligible at a later date. However, many deferrals are indefinite meaning that donation are not accepted at any point in the future, constituting a de facto ban. Even men who have monogamous relations with their same-sex partner are found ineligible.