Ticket 380: Is support of TAB as a whitespace character required or not?

§2.2 says:

Whitespace characters include the space and newline characters. (Implementations may provide additional whitespace characters such as tab or page break.)

However, §7.1.1 has:

⟨intraline whitespace⟩ → ⟨space or tab⟩ ⟨whitespace⟩ → ⟨intraline whitespace⟩ | ⟨newline⟩ | ⟨return⟩

So §2.2 implies that supporting tabs is allowed but not required, yet §7.1.1 implies supporting tabs is required.

I don't have access to my suite of Schemes today, so I can't verify the state of the art.