The Belgian National Society website has published an update on the restrictive antenna requirements imposed by the Flemish Government.
It would appear that Flemish amateurs who transmit less than 175 hours a year are required to submit forms to the Government bureaucrats for each antenna they have. Multi-band antennas require multiple submissions of forms, for instance a tri-band Yagi antenna for 14/21/28 MHz requires three seperate submissions. If antennas change then forms need to be resubmitted.
If transmission are made from an antenna for more than 175 hours a year with an ERP greater than 20 watts then it appears the bureaucracy involved is even more complex.
Notice for Transmitting Antennas (update April 24, 2012)
Notice for transmitting antennas: response of LNE (Government Department) http://tinyurl.com/TxAntennasResponseLNE
July 2011 Radio Amateurs in Flanders hit by SAR
LNE – Department of Environment, Nature, and Energy of the Flemish government http://www.lne.be/
Royal Union of Belgian Radio Amateurs (UBA)