Incorporation by Reference (Einbeziehung durch Verweisung)

All testamentary dispositions in a Will must satisfy the formalities of a Will in order to be valid. It is permissible for a will to refer to another valid testamentary disposition. In this case, this is also referred to as incorporation by reference (Einbeziehung durch Verweisung). On the other hand, the testator may not refer to documents that do not comply with the testamentary form with regard to the content of the testamentary disposition (so-called "testamentum mysticum"). However, reference is permitted for the purpose of explaining the testamentary provisions in more detail, because it is then only a matter of interpreting the Will that has already been made formally valid (see BGH of 10.11.2022 - IV ZB 30/20).