Did you know that NULL is a “Boolean value”? Hmmm…

PL/SQL User’s Guide and Reference (9.2 and 10.2): “NULL Statement”

“The NULL statement and Boolean value NULL are unrelated.”

I can understand that this is to draw a distinction between “NULL” as a procedural statement and “NULL” as a literal. But why is NULL specifically identified as Boolean? So, the NULL statement is somehow related to NULL strings, NULL numbers, and NULL dates?

(I won’t even mention the problem with calling NULL a value, something which is prevalent throughout the literature, including the SQL standard.)