I should consider possible misunderstandings. Maybe "code postal" is being mistyped, or it's part of a filename. They might be searching for a software or database that handles postal codes in a specific region (like 67 in France) and is packaged as a RAR archive for free download. Alternatively, it could be unrelated and they're talking about creating a new folder with a specific naming convention involving postal codes and RAR files in a free software context.