In real estate what does qualified fee mean?

When the rights of ownership in real estate are dependent on the occurrence or non-occurrence of a certain event, it is known as a qualified defeasible fee estate.
A fee simple qualified estate is a fee simple estate that is subject to limitations by the grantor. There is some condition or special limitation attached to it that may cause it to revert to the grantor.
  • A conveyance to Charles as long as he maintains the property as a working farm. When the working farm is no longer feasible the property would revert to the grantor.
  • A conveyance of undeveloped land owned by a church that restricts it from being used to build an establishment that serves liquor.
  • A conveyance for a nominal sum to a town for a tract that can only be used for a public park.