First discovered by Douglas Adams and then formalised by the German Pirate Party, Vogonism describes a manner of acting such that information is kept hidden in public sight. In case of complaints about the lack of information available, vogonists usually refer to the public availability of said hidden information.
A distinctive property of vogonism is the establishment of an inscrutable network of communication channels and modes, as well as inconsistent use of those: In that manner, information is avoided to be present where recipients expect it, even if other, related information already had been transmitted over the same channel.
A vogonic information system excels in limiting the effective use of it to a small, inner circle of recipients.
Being a general concept, it applies to code styles and documentation as well as wikis and any other place where you can hang signs saying "Beware of the Tiger". Contrast Hoare Property.