In the type system used by Super Smash Bros. Brawl, there are many moves that are typeless. Attacks are generally coded as being typeless for two reasons: the attack does not fit into any other type, or the attack does not appear in the Subspace Emissary. Many attacks outside of playable characters' movesets are typeless. In the case of enemies, their hitboxes do not have the ability to be given a type, and are therefore also typeless.
As typeless is the default type of all hitboxes, maintaining a list would be futile, and as such any attacks that are not listed on any other type pages can be assumed to be typeless.