RS.CLIPPY.DOC_SUSPICIOUS_FOOTNOTES

Looks like a link or footnote ref, but with no definition

This checker is a Clippy lint created by The Rust Project Contributors. The documentation shown here is a copy of the original documentation for: doc_suspicious_footnotes. Copyright ©2025 The Rust Team. All rights reserved.

What it does

Detects syntax that looks like a footnote reference.

Rustdoc footnotes are compatible with GitHub-Flavored Markdown (GFM). GFM does not parse a footnote reference unless its definition also exists. This lint checks for footnote references with missing definitions, unless it thinks you're writing a regex.

Why is this bad?

This probably means that a footnote was meant to exist, but was not written.

Example

/// This is not a footnote[^1], because no definition exists.
fn my_fn() {}

Use instead:

/// This is a footnote[^1].
///
/// [^1]: defined here
fn my_fn() {}