This is a marker for current and future maintenance (making sure the games are listed by official titles instead, and to properly identify the fan translations later on).

The "uses a translated title from another product (even if correct)" bit covers cases where one game on a platform is listed by, for example, an English title the game was released as on another platform even though it never was used for the game on the one it's now applied to. These are essentially correct in terms of the translation, but not in terms of official releases, ergo they belong to the same category as fan translations (known by fans by such title).