Incorporation by reference.

(1) A writing in existence when a will is executed may be incorporated by reference if the language of the will manifests this intent and describes the writing sufficiently to permit its identification.

(2) A will may dispose of property by reference to acts and events which have significance apart from their effect upon the dispositions made by the will, whether they occur before or after the execution of the will or before or after the testator’s death. The execution or revocation of a will or trust by another person is such an event.