***If, as you wrote, the most practical solution, and the one upon which there is more consensus, is to include a system in the list when: 1) Both LRTA and UITP list it as a metro; 2) There is no other conflicting source listing it as a "light metro"; then we should add Catania metro in the list. It would be discriminating not to do so. The User AndreaTartaglia posted a link ( http://oi64.tinypic.com/2wpp2l1.jpg ) providing proof that UITP includes it in their list. Moreover, as the User 93.57.250.62 pointed out, I reckon that there is a slight semantic misunderstanding about the the criterion of "high passenger capacity". The word capacity denotes how much a system can carry, not how much it actually carries at the moment: i.e. it relates to the capacity of the infrastructure, which Catania's metro indeed has.