C72: This likely refers to the 72nd chapter of a doujinshi or a specific compilation of fan art and stories. In the context of doujinshi, chapters or volumes are often denoted by numbers or codes like this.
In Naruhodou Naruhodo Tsunade no Inchiryou, the "addition" might be: C72 : This likely refers to the 72nd
The story is set during the Naruto Shippuden era, typically following Naruto's return to the village after training with Jiraiya. The "proper write-up" of this specific doujin usually highlights the following elements: Title: C72 Naruhodou Naruhodo Tsunade no Inchiryou Naruto
Given its origins at Comiket, this is an unofficial fan work and is not part of the official Naruto manga or anime canon Narutopedia The story is set during the Naruto Shippuden