There is no feedback to my first post, perhaps I should have provide more background on Total Commander (TC) dual pane file manager and its File Comment scheme.
Dual pane file managers are *highly evolved, super productive* file management tools that could be a good match for disorganised book readers. For instance, TC which I'm familiar with, has excellent duplicate files search, multi-rename tool and file synchronisation, on top of the efficient dual pane file management. There is a learning curve to Dual pane file managers before the finger-tips acquire the muscle memory to perform the file magic intuitively. If this is new, you may wish to look up Orthodox File Manager (
www.softpanorama.org/OFM/) for a *long* read on their merits. Like Calibre, each of these file tools has its community of fans, power users and add-on developers dedicated to enlightened file management.
The TC's file comment scheme actually has its lineage in JPsoft's 4DOS software, dating back to the DOS and Bulletin Board era. Bulletin board and software that supported this simple metafile scheme would extract and display the more meaningful file descriptions alongside the 8 characters short filename used in those days. This became redundant when long filename came along, nevertheless people continued to use it to store metadata for their PC files. Tools that still support this metafile scheme today are:
* Dual pane file manager: Far Manager (open source), Double Commander (open source), Total Commander (44 USD), Directory Opus (85 AUD), ....
* File viewer: Xnview (Free for personal use), ....
If dual pane file manager doesn't appeal, Xnview has a more conventional Windows Explorer style interface and supports the same File Comment scheme. There is another community that is even more in need of metafile info than compulsive ebook hoarders: prolific photographers who need to tag their photo shots. In that community, Xnview is highly regarded as a very capable image viewer and management tool.
While this ebook tagging scheme I'm exploring has a wider applicability as metafile for all types of files, not just ebooks, it's admittedly a niche workaround compared to full ebook management software like Calibre. It appeals to me mostly because it's another use of the file tool I'm already familiar with and neatly addressed my modest needs to put order to my ebooks. Hopefully the info is useful to others with similiar needs.