You might find some eminent agreement[1], though to be fair he was talking about relational DBMS, not SQL DBMS. See rule 0 and 1:

Even table names, column names and domain names are represented as character strings in some tables. Tables containing such names are normally part of the built-in system catalog. The catalog is accordingly a relational data base itself — one that is dynamic and active and represents the metadata (data describing the rest of the data in the system)

[1] The Twelve Rules, E.F.Codd https://reldb.org/c/index.php/twelve-rules/