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