What is "agaricomycetidae"

Agaricomycetidae is a subclass of mushrooms, in the phylum of Basidiomycota. The MycoBank number for this subclass is MB501298. The name Agaricomycetidae had previously been named by Locquin (1984), but his publication did not contain a Latin diagnosis and it is therefore invalid under the International Code of Nomenclature for algae, fungi, and plants.