Personally, I keep records in excel. Each field is separate column and storage location is simply a numbered box or tube.
Have fields for title, year, size, NSS number, folded/rolled, card #s for LCS, double sided, location and notes. Can select and sort on any of them.
Since 90% of my stuff is US, I just keep country or origin in the notes, but it would be simple to add a column. I see no point in coming up with a coding number. If you want universal coding, simply agree on the order of these fields and convert to a CSV output (comma separated values)
Example:
"Bandwagon The",1/2-sh,,1953,Good,53/404,Rolled,framed on wall,Style B. Tear on top/taped. Sm tear on btm.
(for some reason the site kept rejecting the post until I reformatted)
Oh yeah, the fields are Title, Size, LC #(s), Year, Condition, NSS #, Rolled/Folded, Location, Notes