[Havoc]

I know and understand the reasons why Calibre works like it does and for some things it would work fine for me. But not for everything. And keeping everything twice through exporting isn't really an alternative.

Most of my books are scans of old books in pdf. Epub isn't an option as they are full of diagrams and photo's. And the epub versions are just ocr's full of scrambled words. And I'd like to keep the filename so I can know if I already downloaded it. So I also cannot change the folders because that would make it impossible to compare without first downloading with is what I'd like to avoid.

Another part are manuals. These are sorted by manufacturer and device and I want to be able to keep them that way so I can access them without having to open another application first. The same goes for a rather large collection of datasheets of electronic components and electric standards.

Like in the manuals, there might be a repair manual that contains info about some generic part. Would be nice to be able to tag it so that a search could turn up that repair manual for some unrelated device that contains the same part. And the datasheets are refered to frm the pcb design software. So searching outside of it would be easier with some tags but re-doing the whole component database isn't an option.

But having a title that actually says something (instead of some abstract filename) and some tags would make it a lot easier. I don't mind if it would add a bunch of metadata files around in the folders.

Maybe some simple database would be a good solution but are there pre-defined versions around for this? Or at least something easy to configure. Databases are out of my comfort zone.