In Re Keen [1937] Ch 236, property was left to two people to dispose of ‘as may be notified by me to them’ or either of them ‘during my lifetime’.
A sealed envelope containing the terms of the trust was given to one of the trustees before the will was executed. The Court of Appeal held that the trust failed because:

1. The will referred to a future communication, which was inconsistent with a communication already made, so the trust would fail for inconsistency with the will;
2. There was a reference to future communication, which was not permissible.