Judgment of Bulgarian Supreme Court (Върховен съд) No. 327, Civil Case No. 257/92 of January 14, 1993

Rationes Decidendi:

An arbitral tribunal in voluntary arbitration is not a judicial authority (such as authorities with special jurisdiction), because of the contractual basis of arbitration. Authorities with special jurisdiction are different, because they were founded by the state (a state authority). This is not the case with commercial arbitration.
Awards rendered in [voluntary] arbitration need not comply with judicial practice and are not subject to any ordinary or extraordinary judicial review, nor are they subject to the laws regulating extraordinary review and the annulment of final and binding decisions of public authorities.
Arbitral tribunals resolve disputes in accordance with their own (internal)17 rules. The court is not allowed to review arbitral awards from the perspective of their [material] validity, because they were rendered under rules different from the CCP [BUL] [rules applicable to court proceedings], and the parties [having agreed on the arbitral clause], intentionally refused intervention by the courts (prohibition of judicial review of arbitral awards/prohibition of revision au fond). Another difference between the two types of proceedings consists of the fact that courts have a varying status within the judicial system (system of public authorities).