Organization modes

A library's organization mode decides how files become books: every file on its own, or everything in a folder together. You choose it when you create the library, and it can't be changed afterwards.

One book per file

Every file is a book. Nothing is grouped, so there are no surprises.

Books/
├── Pride and Prejudice/
│   ├── Pride and Prejudice.epub   ← book 1
│   └── Pride and Prejudice.pdf    ← book 2
└── Dracula.epub                   ← book 3

Good for loosely organised collections, several books per folder, or when you'd rather decide yourself which files belong together. To join two formats afterwards, select the extra format's book and use Attach to Another Book from the selection bar's menu.

One book per folder

Everything in a folder is one book, with one entry per format. The folder is the boundary; folders above it (authors, series) don't matter.

Books/
└── Jane Austen/
    ├── Pride and Prejudice/
    │   ├── Pride and Prejudice.epub   ← ┐ one book,
    │   ├── Pride and Prejudice.pdf    ← ┘ two formats
    └── Emma/
        └── Emma.epub                  ← another book

Good when each book has its own folder, which is how most well-kept libraries look, and when you have ebooks and audiobooks of the same title.

Audiobooks alongside ebooks

A folder of audio tracks inside a book's folder joins that book, so the EPUB and the audiobook are one entry:

Books/
└── Treasure Island/
    ├── Treasure Island.epub   ← ┐
    └── audiobook/                 │ one book:
        ├── 01.mp3             ← │ EPUB and audiobook
        └── 02.mp3             ← ┘

In both modes

• A folder with two or more audio files and no other books is one audiobook, named after the folder.
• Files at the top of a library folder (not in a subfolder) are books of their own.
• A physical book gets its file attached automatically when a file with exactly the same title turns up in the library.

Choosing

If each book has its own folder, use One book per folder. Otherwise use One book per file. To switch an existing collection, create a new library with the other mode for the same folders and delete the old one (reading progress on the old library's books is lost, so do this early).

Auto-detect (older libraries)

Libraries created before these two modes existed use Auto-detect, which you'll see marked "legacy" in their settings. It can't be chosen for new libraries. Auto-detect guesses which files belong together by comparing names:

• File names are normalised first: extensions, underscores, format tags like [epub] or (audiobook), part and disc numbers, trailing author names and moved articles ("Time Machine, The") are ignored.
• Inside a folder, files whose names match the folder's name (allowing for edition words such as "Unabridged" or "Illustrated", and small differences) are one book.
• Files that look like numbered volumes (Book 2, Vol. 3, #4, 02 - …) stay separate books even in the same folder.
• At the top of a library folder, only files whose normalised names are identical are grouped.

It usually works, but when it guesses wrong the fix is renaming files. A new library with one of the modes above behaves predictably.