Exceptions to this rule are a Pesach sacrifice brought on Passover, and a sin-offering. These two, if slaughtered not for their own sake, are completely invalid.
Ravina said to Rav Pappa, "It's a pity that you were not within Shabbat boundary and could not come to us Friday night, for Rava asked a great question and resolved it." What was it?
Rava found this contradiction: the sacrifice is not counted if slaughtered for a "wrong designation," but if there is no designation, it is valid. A woman's Get, on the other hand, has to be written expressly for her, but if there is no designation, it is invalid. And he answered: a sacrifice, without a designation, is intended for its sake, but a woman, if not otherwise specified, will continue to be married, and does no intend to be divorced.
Art: Gerard Ter Borch - Woman Reading a Letter