404. The president, if he considers it advisable, may assign one or several assessors to a commissioner.
The president may also, if he considers it advisable owing to the complexity or importance of an appeal, designate three commissioners to hear it, one of whom shall preside at the proof and hearing.
In the case of the second paragraph, the decision of the board of appeal is taken by a majority of the designated commissioners and if there is a dissenting commissioner, the grounds for his disagreement shall be recorded in the decision.