Currently, the Doujinshi tag is used to classify unprofessionally published manga. For the most part, this means secondary works such as this. However, there are some original doujinshi in the mix, such as this.
The common practice seems to be to append "(Doujinshi)" or "(Doujin)" to the name of a secondary manga, whereas original doujinshi are titled as-is. This method, however, makes searching for original doujinshi very difficult, since the search does not support excluding terms from the name. To address this, I propose making a separate Secondary tag, denoting manga that are intentionally set in the universe of another work. The tag should also include official secondary manga, such as this.
The common practice seems to be to append "(Doujinshi)" or "(Doujin)" to the name of a secondary manga, whereas original doujinshi are titled as-is. This method, however, makes searching for original doujinshi very difficult, since the search does not support excluding terms from the name. To address this, I propose making a separate Secondary tag, denoting manga that are intentionally set in the universe of another work. The tag should also include official secondary manga, such as this.