1) The appellee himself is in the context of speaking. Because cousins belong to mutual appellation, they usually don't call themselves "cousins" in front of their cousins, but mainly refer to their names, table characters (or fine print) and birth names (or nicknames).
2) Self-appellation means that the appellee himself is in a language context, which is not applicable because cousins belong to mutual appellation.
3) It is reported that the appellee himself is in a speaking context, and when introducing his cousin to strangers, he can call him "cousin", so this context applies.
4) Returning to the address, the address object is not present, and the cousin can be said to be "cousin", so it also applies to "returning to the address". Written appellation can be divided into two types to discuss.
1) paraphrased narrative, books can be written as "cousins" when explaining the relationship between the appellee and himself to strangers, so it is applicable.
2) Direct address refers to letters and telegrams sent to the appellee, which are mostly written as cousin's name, table character (or fine print), birth name (or nickname), and can also be used as "cousin" or "cousin", so it is also applicable.