We no longer have any idea what an object or subject is. We just allow one word to be multiple at once. "The annual salary should be what(ever) is registered in the social security authority." is how we'd say it. By the way, you can make pretty much anything and everything abstract into a plural concept by adding 's, or just s, to the end. zzzzz --> Too many z's. - Too many "thats" - . If its especially ambiguous you could put quotes around the new/fake word.