"BS" is the simplified American initialism for Baccalaureate Scientate. In most other English-speaking countries the acronym "B.Sc." is used. It's like the way they misspell "colour" and "labour". A cute affectation that we may well snicker about behind their collective backs but in the end it's meaningful and respectable and we move on.

"CS" on the other hand is not short for "computer programmer job training" so I'm confused by the expectation of the original Ask HN question.