Paragraph 21 exempts contracts that are awarded under the 'public service obligations regulations' which are defined in section 136(11) of the Railways Act 1993.
Mae paragraff 21 yn esemptio contractau a ddyfernir o dan reoliadau rhwymedigaethau gwasanaethau cyhoeddus a ddiffinnir yn adran 136(11) o Ddeddf Rheilffyrdd 1993.