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:
The contracting parties' full names or sovereign titles are often included in the preamble, along with the full names and titles of their representatives, and a boilerplate clause about how their representatives have communicated (or exchanged) their full powers (i.e., the official documents appointing them to act on behalf of their respective states) and found them in good or proper form.

Question:
In addition to their full names, what else is included in the preamble that identifies the parties to a treaty?

sovereign titles