---
title: "EPUB 2 series metadata"
---

> Documentation Index
> Fetch the complete documentation index at: https://kmworks.date/llms.txt
> Use this file to discover all available pages before exploring further.

# EPUB 2 series metadata

When an EPUB has no EPUB 3 `belongs-to-collection` / `group-position` properties, KMServer falls back to the OPF 2 `<meta name="…" content="…"/>` form for the series title and the book's number/numberSort:

- `calibre:series` / `calibre:series_index` (calibre)
- the bare `series` / `series_index` (common in fan-packed light-novel EPUBs)

The Java version only reads the EPUB 3 property form.

Source: https://kmworks.date/server/enhancements/epub2-metadata/index.mdx