So-and-So

"So-and-so" is a phrase often used in colloquial English vernacular to describe a person whose name the speaker can't remember or does not know. Usually, it connotes a meaning of unimportance.
==Significance to Stevens==
Stevens has a poem titled "So-And-So Reclining on Her Couch." Some believe that this "so-and-so" is referring to Modigliani's elongated woman, though Stevens refers to a Mrs. Pappadopoulos at the end of the poem. Pappadopoulos seems to be a Greek name, though the exact personage of Mrs. Pappadopoulos, the so-and-so, is still unknown.