User blog comment:Denis Maksudov/Slowly growing ordinal function and FS up to BHO./@comment-28606698-20170402064919/@comment-28606698-20170402110109

Yes, an uncountble ordinal has FS with lenght $$/Omega$$ and we can write $$/Omega(\alpha)$$, where $$\alpha$$ is any countable ordinal (not only natural number)