The International Law Commission contributes to filling gaps in treatment and interpretation of international treaties. They do so in different ways.
In the case of the recently completed topics were on the theme "The effects of armed conflict on the convention 'classic draft articles with commentary. For a topic Reservations to treaties is primarily the result of an aid to interpretation (Handbook for practice).
In the case of new themes "provisional application of treaties" and "subsequent agreement and subsequent practice in the interpretation of international treaties" is an institution governed by foundations in Art. 25 and Art. 31 of the Vienna Convention (1969), which raise a number of theoretical and practical questions solution.