When building or editing Urban Items, you can add related links. This is an excellent thing to do because it adds enormous value to the Urban Item. It means that for additional information you can provide interested people with a direct link to other websites about the building and save them a lot of time searching the web. The more related links there are, the better it is. For adding more than one link it is necessary that you separate the links by introducing a comma and a space character. Otherwise there will only be one very long link, which will lead nowhere. Do it the same way, when you add tags.
Have fun!