102.129—Communications prohibited.
        
        (a) 
         Such communications, when written, if copies thereof are not contemporaneously served by the communicator on all parties to the proceeding in accordance with the provisions of  § 102.114(a).
    
    
        
        (b) 
         Such communications, when oral, unless advance notice thereof is given by the communicator to all parties in the proceeding and adequate opportunity afforded to them to be present.