QDoc manual is inconsistent with --help output

On a QDoc manual-01 page presented example uses single dash options like -outputdir and -installdir. But qdoc's --help output shows single letter options with single dash, and long options with double dashes. So, which is which?

Apparently, the tool seem to support both styles. But what the heck is this inconsistency? It's not even third-party blog post. So, it should be fixed.