Files containing site model symbols from previous versions can be easily converted.
When you update a site model from a previous version, you are prompted to convert to the new site model. If the file contains more than one site model symbol, an alert dialog box prompts for the selection of one of the symbols to be converted to the primary site model object. The remaining symbols become snapshots of the primary site model.
Site model classes that were necessary for previous versions remain in the file, although they are no longer used.
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