# EPUBCheck OPF-014: The property … should be declared in…

Source: https://epublab.com/epubcheck/opf-014/ (updated 2026-11-03)

EPUBCheck OPF-014 is an error message: “The property "…" should be declared in the OPF file.” A content document uses a feature that must be declared on its manifest item, and the declaration is missing.

- Official message (EPUBCheck 5.4.0): The property "%1$s" should be declared in the OPF file.
- Default severity: Error

## Typical causes

- Inline SVG without properties="svg", MathML without "mathml", scripts without "scripted", or remote resources without "remote-resources" on the manifest item.

## How to fix it

- Add the property EPUBCheck names to that document's manifest item, for example <item id="c1" href="ch1.xhtml" media-type="application/xhtml+xml" properties="svg"/>.
- Separate several properties with spaces.

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