 according to roman catholic church teaching, a sacramental character is an indelible spiritual mark (the meaning of the word character in latin) imprinted by three of the seven sacraments: baptism, confirmation, and holy orders. this teaching is expressed as follows in the catechism of the catholic church, 1121:catechism of the catholic church, 1121  the characters these three sacraments imprint are held to differ from each other, with each character remaining indelible, so that nobody can receive the sacrament in question more than once. the doctrine of the sacramental character is thus a particular expression of the long-established teaching that baptism, confirmation, and holy orders may not be repeated, e.g. no one may be baptized more than once. one who receives a lower grade of holy orders may receive a higher. thus, though one who has been ordained a deacon may not again be ordained a deacon, he may be ordained a priest. similarly, while a priest may not again be ordained a priest, he may be ordained a bishop. there is no higher grade to which a bishop may be ordained. each higher grade is considered to confer a deepening or intensification of the character of holy orders. if it is doubtful whether a person has received one of the three sacraments in question, the sacrament may be administered conditionally (e.g., using the words "if thou art not baptized, i baptize thee in the name of the father and of the son and of the holy spirit"); but such an administration, being valid and effective only to the extent that no valid administration of the same sacrament has already occurred, does not in any event constitute an effective repetition of a valid previous administration of that sacrament. the doctrine of the sacramental character was dogmatically defined at the 16th century council of trent, but was held for more than 1000 years before, and was written about by augustine of hippo. the catechism of the catholic church, 698 explains as follows the significance of the image of "seal", used as an alternative to that of
Catholic_theology_and_doctrine Sacraments