XS_MULTIDRAWING_KEEP_OBSOLETE_DRAWINGS
Category in Advanced options dialog: Drawing properties
Use this advanced
option for controlling the views and multinumbers of deleted assemblies in multidrawings. Set this advanced option to TRUE to preserve the views
of deleted parts and assemblies and to reserve the multinumbers of the deleted parts
and assemblies. Set it to FALSE to reuse the multinumbers of the deleted assemblies and to delete
the views. The default value is FALSE.
This advanced option is model specific and the setting is saved in the options database.