I'm currently compiling the open cluster section of a pretty huge database that contains every object in the Interstellarum atlas and cross lists it with all of the major paper atlases and references currently in use by amateurs, as well as trying to keep relevant data updated for each object. One of my present issues is dealing with some of the less-known catalogs and their abbreviations; the abbreviations list in ISDA isn't always helpful.

One such issue is the abbreviation Rie, which involves three or four obscure open clusters that are indicated for larger scopes. I've been all over the web looking for the catalog that Rie might reference and have struck out; it doesn't stand for Reiland, which is represented by one object and listed separately (and in any case, the spelling is different). Even Archinal & Hynes doesn't seem to help. Does anyone with a better grasp of the professional materials know what catalogue Rie might represent?