  In recent years, the stars of the Of?p category have revealed a wealth of
peculiar phenomena: varying line profiles, photometric changes, and X-ray
overluminosity are only a few of their characteristics. Here we review their
physical properties, to facilitate comparisons among the Galactic members of
this class. As one of them has been proposed to resemble the magnetic oblique
rotator Theta Ori C, though with a longer period, this latter object is also
included in our study to illuminate its similarities and differences with the
Of?p category.
