# EPUBCheck RSC-033: Relative URL strings must not have a…

Source: https://epublab.com/epubcheck/rsc-033/ (updated 2026-11-03)

EPUBCheck RSC-033 is an error message: “Relative URL strings must not have a query component, but found one in "…".” A relative URL contains a query string (?…), which EPUB does not allow because there is no server to answer it.

- Official message (EPUBCheck 5.4.0): Relative URL strings must not have a query component, but found one in "%1$s".
- Default severity: Error

## Typical causes

- Links copied from a website, such as page.xhtml?id=3.

## How to fix it

- Remove the query part from the URL; use a #fragment to point inside a document.

Message text and severity: EPUBCheck (W3C, BSD-3-Clause). Explanation: EPUBLab.