@expectedException

The @expectedException tag declares the Throwable a test method is expected to throw. It is an old PHPUnit-era convention that predates the expectException() method call and is unrelated to PhpStorm itself.

Parsing a @expectedException tag produces a ExpectedExceptionTag instance, carrying the parsed $type alongside the $name and optional $description every Tag already provides.

A historical PHPUnit convention, not a PhpStorm tag.