CONTRIBUTING
The Perl code as such is fairly trivial (which does not imply free of bugs), so there is probably little opportunity to contribute interesting things. However, the tube lines and stations will probably evolve. I would be grateful to be informed about any such changes (or, indeed, of errors of mine). The best way to contribute is to create an issue and to list any updated line and station information in plain UTF-8 text, or to attach this information in a plain text file. Do not change the XML file, since this is mechanically generated from a different, internal file format.