Belgian dentists (i.e. dentists working in Belgium) who do not send a registered letter to the INAMI within 30 days of the publication of the so-called "national agreement" are deemed contracted and must therefore abide by a number of rules without any noticeable benefit.
The letter rejecting the "national agreement" should be in French (or Dutch) and a model can be found on page 9 of the document hereunder.
The date of publication in the Official Journal ("Moniteur belge") is not known at this stage... because the Minister of Social Affairs can still veto the "agreement"!