Reference is an adjective that comes from the kanji for the Japanese word "任食". Generally speaking, a Japanese restaurant is also known as a Japanese buffet.

The adjective "放题" is not only limited to food, but has been popularized by a number of people, depending on the sentence in which it is used. For example, the adjective "reading playback", "music playback", "movie playback", and so on, generally refers to a medium that provides a large amount of information, and allows the user to satisfy a certain kind of information.