Surly management says: Warning: wearing this shirt may lead to laughter, disgust, or loss of employment. But if you’re not worried about these things, get down to your local shop and ask them to order you one.
Round the offices of Dirt Rag’s most thorough editors, the main reason for laughter, disgust, or loss of employment would, of course, be the utter tastelessness of that upside down apostrophe.
(Technically, it’s not an apostrophe at all, but a single open quotation mark, but why be anal about it? He said. Being anal about it.)