This is a tracking category. It is used to build and maintain lists of pages—primarily for the sake of the lists themselves and their use in article and category maintenance. It is not part of the encyclopedia's categorization scheme. More information: This category is hidden on its member pages—unless the corresponding user preference (Appearance → Show hidden categories) is set. These categories are used to track, build and organize lists of pages needing "attention en masse" (for example, pages using deprecated syntax), or that may need to be edited at someone's earliest convenience. These categories also serve to aggregate members of several lists or sub-categories into a larger, more efficient list (discriminated by classifications). Typically, tracking categories are automatically populated by templates invoked in pages or by the MediaWiki software (see Special:TrackingCategories for an overview of the latter).

Administrators: Please do not delete this category as empty! This category may be empty occasionally or even most of the time.

This category is automatically populated by {{ rail line one to three}} and related templates being passed certain illegal parameters or combinations of parameters. As of December 2010, these combinations are:

• in {{ rail line one to three}}, {{ rail line three routes}} - |col= with one or more of |col1=, |col2= and |col3=
• in {{ rail line one to two}}, {{ rail line two to one}} - |col= with one or both of |col1= and |col2=
• in {{ rail line one to two}}, {{ rail line two to one}} - |route= with one or both of |route1= and |route2=
• in {{ rail line one to two}} - use of any of |previous1=, |previous2=, |next=
• in {{ rail line two to one}} - use of any of |previous=, |next1=, |next2=

Action:

• if all colour values should be the same - remove all except |col=
• if there should be two or more different colours - remove |col= and ensure a value is provided for each of the others.
  • If the correct colour value is unknown, use |coln={{ temporary rail colour}} .
• if all route descriptions should be the same - remove all except |route=
• if there should be two or more different route descriptions - remove |route= and ensure a description is provided for each of the others.