Act of making a will; non-delegable; exceptions

The law on succession requires that the making of a will be a purely personal act. However, there are aspects of will-making that can be delegated.

What are those that cannot be delegated to third persons? [1] designation of heirs, devisees and legatees; [2] duration/efficacy of designation; and [3] determination of portions, when referred to by name. (Art. 785 of the Civil Code)

What are those that may be delegated to third persons? [1] determination of a person, persons, institution or institutions falling under a class specified by testator; and [2] the manner of distribution of property specified by testator. (Art. 786) This rule is similar to that in the concept of delegation of powers in political law. The testator (person delegating) must specify the limits and guidelines that the person designated (delegate) must comply with in carrying out the distribution of the estate.