This Javadoc tag isn't being recognised by the Javadoc parser. This can happen very easily if the tag is malformed in some way.

Common cases for {@link tags include:

• Mismatched end braces, for example {@link Foo)
• Totally malformed links, for example {@link #Optional.empty()} (should be {@link Optional#empty()})

Common cases include, for {@code tags:

• The tag not being terminated correctly, i.e. via a parenthesis ({@code foo))
• {@code being used where it isn't accepted, e.g. as the first argument to @param (@param {@code myParam} a parameter)
• Unmatched curly braces in large blocks...

Unmatched curly braces can be particularly hard to spot, e.g.:

/**
 * Should be used like:
 *
 * <pre>{@code
 *   Frobnicator frobnicator = new Frobnicator() {
 * }</pre>
 */
interface Frobnicator {}

Which should be:

/**
 * Should be used like:
 *
 * <pre>{@code
 *   Frobnicator frobnicator = new Frobnicator() {
 *   };
 * }</pre>
 */
interface Frobnicator {}

Suppression

Suppress by applying @SuppressWarnings("UnrecognisedJavadocTag") to the element being documented.