unalias mars.levtype;

if(localDefinitionNumber == 3) { 
	constant marsType   = "oldim"; 
	alias mars.type     = marsType; 
	alias mars.ident    = indicatorOfTypeOfLevel; 

	# Just a guess 
	if(marsStream < 1024) {
		alias mars.ident    = marsStream;
	}

	#unalias mars.param; 
	unalias mars.step; 
}

if(localDefinitionNumber == 24) { 
	unalias mars.param;
	unalias mars.step;
}