Virgule

"O, whoreson slash! Thou unnecessary character!"
Shakespeare, As You Lick It, I, iii

The slash ( / ), also known as the virgule, has several uses, most of which (sayeth the punctuation guide) one should avoid in formal writing.

Never use it when you mean “or”. If you need to convey that conjunction, use it: It doesn’t take up much space and no-one will mind.

On the subject of conjunctions, never, ever , ever use the expression and/or.

There’s just one Slash that looks good in public, and he’s in Guns ’n’ Roses.