Hi veronica I was reading your change in ClassDescription>>definition aStream cr; tab; nextPutAll: 'category: '; store: self category asString. replaced by store: (self environment organization categoryOfElement: self name) asString. and I'm wondering why this is needed? Because I was thinking that I would prefer to have category fixed. Now category Class>>category "Answer the system organization category for the receiver. First check whether the category name stored in the ivar is still correct and only if this fails look it up (latter is much more expensive)" | result | self basicCategory ifNotNil: [ :symbol | ((self environment organization listAtCategoryNamed: symbol) includes: self name) ifTrue: [ ^symbol ] ]. self basicCategory: (result := self environment organization categoryOfElement: self name). ^result