[ULPIANUS libro quarto ad edictum. ] §2.14.5.prConuentionum autem tres sunt species.
[ULPIANUS, On the Edict, book 4] Now, there are three classes of agreements.
aut enim ex publica causa fiunt aut ex priuata: priuata aut legitima aut iuris gentium.
For they are made either from a public cause or from a private cause; and a private one is either statutory or under the law of nations.
publica conuentio est, quae fit per pacem, quotiens inter se duces belli quaedam paciscuntur.
A public agreement is one which is made through a peace treaty, whenever military commanders agree on certain terms among themselves.