Oregon Revised Statutes Probate Law § 112.255

(1) A will is lawfully executed if it is in writing, signed by or at the direction of the testator and otherwise executed in accordance with the law of:

(2) A will is lawfully executed if it complies with the Uniform International Wills Act.

(3) 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.

(4) A will may dispose of property by reference to acts and events that have significance apart from their effect upon the dispositions made by the will, whether the events occur before or after the execution of the will or before or after the testator's death. The execution or revocation of another individual's will is such an event.