Proper may refer to: Mathematics Proper map, in topology, a property of continuous function between topological spaces, if inverse images of compact subsets are compact Proper morphism, in algebraic geometry, an analogue of a proper map for algebraic varieties Proper transfer function, a transfer function in control theory in which the degree of the numerator does not exceed the degree of the denominator Proper equilibrium, in game theory, a refinement of the Nash equilibrium Proper subset Proper space Proper complex random variable Other uses Proper (liturgy), the part of a Christian liturgy that is specific to the date within the Liturgical Year Proper frame, such system of reference in which object is stationary (non moving), sometimes also called a co-moving frame Proper (heraldry), in heraldry, means depicted in natural colors Proper Records, a UK record label Proper (album), an album by Into It. Over It. released in 2011 Proper (often capitalized PROPER), a corrected release in response to a previously released online video or movie that contains transcoding or other playback errors See also Acceptable (disambiguation)