Discover everything you need to know about Texas separate property agreement forms in this engaging and comprehensive blog. This is a document through which the parties agree that particular property will be "separate property" and will not be divided.The document is a partition agreement between two parties to terminate their community ownership of a parcel of land and divide it between them. A marital property partition is an agreement between spouses that allows them to convert community property into the separate property of one spouse. (ii) Is there a partition agreement? (iii) What is the character of the Property? An agreement entered into during the marriage is a Marital Property Agreement and is sometimes known as a "Partition" or. "Postnuptial" Agreement. An agreement entered into during the marriage is a Marital Property Agreement and is sometimes known as a "Partition" or. "Postnuptial" Agreement.