The Rapid Transit category page contains all articles relating to the Rapid Transit DLC, released on the 14th December 2017. This includes all locomotives, operators, locations, tutorials and scenarios. Wiki tutorial pages for Rapid Transit, such as Deutsche Bahn signalling tutorial pages should be in this category. At a later date, wiki guides to DB Signalling, SiFa and PZB will be added.
If you believe a page that is related to the Rapid Transit DLC is not within this category, you can add it by going to the bottom of the relevant page and clicking on the 'add category' button. Then type in 'Rapid Transit' and press the enter key. Then press the 'save' button.