Library catalogs are rich sources for discovery, but a catalog record and a feed item serve different purposes. The catalog aims to describe and locate resources; the feed tells a subscriber what has changed. A useful library Book RSS feed might announce newly cataloged local-history titles, recent acquisitions in a subject, digitized public-domain works, newly available e-books, or corrected records in a special collection. It should not dump every database update without explaining why the change matters.

The design challenge is identity. A single work can have many expressions, editions, printings, formats, translations, and holdings. A catalog may contain separate records for each, while a public feed may need to group them. Before selecting fields, define whether an item represents a work, an edition, a specific copy, a digital object, or an acquisition event. That choice determines the GUID, title, dates, links, and deduplication rules.

Start with a clearly scoped collection question

“New books” is usually too broad. A better scope identifies an audience and an event: new children’s books added this month, digitized maps linked to city-guide research, new titles by local authors, or materials newly available for remote borrowing. A narrow scope supports meaningful summaries and manageable feed volume. It also makes it easier to explain inclusion criteria on the feed landing page.

Document the source system and refresh cadence. Some catalogs expose APIs, exports, OAI-PMH endpoints, or vendor-specific services; others require scheduled reports. The Library of Congress, for example, publishes structured interfaces for its collections. The Library of Congress API documentation shows how a large cultural institution exposes search and item data in machine-readable forms. Your source may differ, but the same principle applies: use supported access methods and respect service terms.

Separate work identity from edition and holding identity

A work is the abstract intellectual creation. An edition or manifestation is a particular publication with a publisher, date, language, format, and often an ISBN. A holding describes an institution’s relationship to a copy or licensed resource. Feed users may care about any of these. A “new translations” feed should distinguish editions. A “now available at our branch” feed is about holdings. A “new works by local authors” feed may group several formats under one item.

Create a stable internal identifier for the feed record and retain external identifiers as attributes. ISBN is useful but format-specific and sometimes missing or reused incorrectly in source data. OCLC numbers, LCCNs, DOIs, repository handles, and local bibliographic IDs can supplement it. Do not concatenate all identifiers into the item GUID; that makes identity change when metadata is corrected. Instead use a canonical record URL or a persistent internal key under your control.

Normalize metadata without pretending every source agrees

Map source fields into a documented model: title, subtitle, contributors with roles, edition statement, publisher, publication place, dates, language, subjects, identifiers, physical or digital format, extent, summary, cover, and access links. Keep the original values or provenance references internally. When two sources disagree about a publication year, do not silently choose whichever arrived last. Apply a stated priority rule or route the record for review.

Names need authority control where possible. “Smith, Jane,” “Jane A. Smith,” and “J. Smith” may refer to the same person, but automated merging can also combine different people. Use authority identifiers when supplied and show the human-readable form appropriate for the audience. Subjects and classifications can help generate topical feeds, yet they should be explained in plain language rather than exposed only as codes.

Define what counts as a feed-worthy update

Catalog systems record many changes that subscribers do not need: punctuation cleanup, internal notes, batch processing flags, or local workflow status. Establish an event filter. New bibliographic records, newly digitized content, new access formats, changed public availability, major metadata corrections, and added holdings may merit publication. Minor technical edits can update the canonical page without reappearing as a new feed item.

Decide how to handle backdated and imported records. A newly migrated record may describe a book added years ago. If the feed is about catalog activity, its item date should reflect when the record entered the new feed scope, while the bibliographic publication date remains a separate field. Label the distinction clearly. Do not set every item’s publication date to the book’s original release year; feed readers use dates to order updates.

Make availability explicit and local

Availability changes rapidly and may depend on branch, license, patron status, region, or time. A feed summary can state broad status such as “available online,” “request from special collections,” or “recently acquired,” but the canonical catalog link should remain the authority for live availability. Avoid embedding short-lived session URLs. If an e-book platform requires authentication, describe the requirement instead of suggesting open access.

For physical books, distinguish bibliographic existence from a copy being on the shelf. For marketplaces or cooperative catalogs, distinguish a record from an offer. A Book RSS feed can link to multiple institutions or vendors, but it should not imply endorsement or current stock unless that information is verified. The used-book marketplace feed guide discusses price, condition, and offer identity in more detail.

Create summaries for readers, not database administrators

A raw catalog note can be dense, abbreviated, or intended for professional interpretation. Write a concise summary that identifies the subject, edition, notable contributors, and reason for appearing in the feed. Preserve important qualifiers, such as facsimile, revised edition, translation, large print, abridged, or volume number. Do not invent a review, quality judgment, or popularity claim. If no summary is available, a transparent metadata-based description is better than promotional filler.

Cover images should come from a source authorized for display and should be associated with the correct edition. When no cover is available, generate a branded card containing title and format. Do not reuse a cover from a different edition merely because the title matches. Include alt text and dimensions, and make the feed useful when images are not displayed.

Publish RSS and OPDS from one normalized collection

RSS and OPDS can complement each other. RSS provides a chronological stream of collection updates. OPDS can expose navigable publication groups, formats, and acquisition relationships. Generate both from the same normalized records so titles, identifiers, images, and links remain consistent. The website should explain the difference and offer the format that matches the user’s goal rather than presenting two unexplained XML links.

For API-driven sources, cache source responses according to policy and retain the time of retrieval. Build feeds atomically: write new files, validate them, then replace the live versions. If the upstream service is unavailable, preserve the last valid feed and display a transparent update timestamp. Do not publish an empty feed that looks like the collection has vanished.

Audit duplicates and edition collisions

Run duplicate checks using normalized title, contributor, publisher, date, identifiers, and edition statements, but send uncertain cases to review. Two books can share a title and year. One ISBN can be entered incorrectly on multiple records. A paperback and e-book may deserve separate edition records but a combined work-level feed item. Keep merge history so a corrected duplicate does not break old item links.

Test the feed with realistic changes: a new title, a corrected author name, a withdrawn digital file, a new branch holding, and a revised edition. Confirm that each event produces the intended update behavior. The BookRSS catalogs page provides a broader field map for Amazon-style catalogs, WorldCat-oriented workflows, Library of Congress data, new books, and used-book marketplaces.

Conclusion

Library catalog RSS succeeds when it translates collection activity into a clear subscription experience. Define whether items represent works, editions, holdings, or events; keep stable internal identity; preserve metadata provenance; and publish only changes that matter to the audience. Availability should point back to the live catalog, while summaries and images remain accurate to the edition. With one normalized model, a library can support web pages, RSS updates, and OPDS discovery without maintaining contradictory records.