A waqf is trust-like instrument created by a Muslim who designates the principle of property that he or she owns as an endowment that henceforth may not be sold, gifted, or transmitted through inheritance, with the result being that the property becomes inalienable in perpetuity. The terms of an endowment are recorded in an endowment deed (waqfiyya) that is drawn up with great care in an effort to eliminate any ambiguity; in the deed, the founder announces the purpose of the endowment, specifies the beneficiaries, and makes provisions for its administration. These deeds are important sources for the history of Muslim societies.