You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
Treaty

Context:
After their adoption, treaties as well as their amendments have to follow the official legal procedures of the United Nations, as applied by the Office of Legal Affairs, including signature, ratification and entry into force.

Question:
In addition to signature and ratification, what legal procedure of the United Nations must all treaties follow after their adoption?

entry into force