If Purge is used in a project file, all unused Familes and types etc. are purged. Not all unused stuff is purged, but that's another wish. Unused items in Families are not purged. To purge Families, you have to open the Family and perform Purge. But if the Family contains nested Families, they're not purged. You havbe to open the nested Family and purge it. And if that Family has nested Families.... you get the idea.
If Families are shared, then purging is a little easier - purge one shared Family and the rest is done also. But not all Families can be shared.
So what's needed is for Purge to purge all familes and nested families as well.
Simon
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