This Cumulus filter can catalogs documents created by Graphsoft's MiniCad version 6.0 or later (The file type is "MC6d").
If a MiniCad file doesn't contain a preview, it is represented in the catalog by a MiniCad icon as its thumbnail. MiniCad 6.0 allows you to save a preview image together with the file. For that, you need to install a plug-in module called "external". Please refer to "About MiniCad MC 6.0 Externals" located in the "About the Adapters" folder.