A more thorough explanation:

A mixed treaty is an international agreement between two or more states that has characteristics of different types of treaties. For example, it may have features of both permanent and transitory treaties or personal and real treaties.

One example of a mixed treaty is a treaty that establishes both mutual defense obligations (like a defensive treaty) and joint offensive capabilities (like an offensive treaty). Another example is a treaty that relates to both ongoing performance (like a permanent treaty) and a one-time act (like a transitory treaty).

Overall, a mixed treaty is a flexible type of agreement that can combine different elements of other treaty types to suit the needs of the parties involved.