newly class instances defined iv kept as symbol?

WebServer class
	instanceVariableNames: 'uniqueInstance'


Object class allInstVarNames
   --> "#('superclass' 'methodDict' 'format' 'layout' 'instanceVariables' 'organization' 'subclasses' 'name'
       'classPool' 'sharedPools' 'environment' 'category'      'traitComposition' 'localSelectors')"

WebServer class allInstVarNames
   -->"#('superclass' 'methodDict' 'format' 'layout 'instanceVariables' 'organization' 'subclasses' 'name'
'classPool' 'sharedPools' 'environment' 'category' 'traitComposition' 'localSelectors' #uniqueInstance)"

				
I found strange that we get a symbol. 

Stef