A slug is the semantic, human-readable portion of a URL, typically appended after the domain name and path to represent the specific identity of a resource or page within a web system, often derived from the title of the content it identifies; for example, in the URL https://lib.jjay.cuny.edu/citing_sources, the term citing_sources is the slug—automatically or manually generated by the content management system (CMS)—that acts as an identifier within a hierarchy, separating pages like /apa7 or /mla9, allowing the site to dynamically retrieve content from a database or file system; unlike full URLs, slugs are often editable and indexable, optimised for search engine visibility and readability, and crucially they are contextual: a slug has meaning only in relation to its parent directory or domain structure, much like how a chapter title depends on its book; modern CMSs like WordPress, Drupal, or LibGuides (used by many academic libraries) treat slugs as modular nodes of information architecture, enabling clean, persistent links that communicate the nature of the page without query strings or session IDs, and in citation practice, the slug is not referenced alone, but its presence ensures traceable citation stability, for instance when linking to specific guides such as /mla9 or /quoting_sources under the John Jay Library site, ensuring students and researchers can reference exact locations within evolving digital ecosystems; ultimately, the slug is not merely URL decor, but a lexical token that anchors structure, metadata and navigability within web publishing infrastructures. A Slug Is Not a Snail.