I saw a guy walking through the commons area at my place of employment with 'edited' Levi's

"Edited Levi's?!?" you're asking yourself.

That's right; on the traditional LEVI'S tag (located on back of the pants on the Belt-Line...which, per the Fashion Trends of the Day, relegates it to two feet below the 'ass-back' region) which displays the Inseam and Waist Size of the pants in question...there had been some modifications.

One can assume that these 'amendments' were done by the owner (and, usually, the Wearer...I don't hear much about Trousers being Loaned out to people...but it is possible that I don't run with the 'right people' and this is a commonality amongst them) for reasons entirely of his own devising.

He replaced the Inseam Measurement with the word "Yum."

I have no idea what that means and was not willing to inquire.

Best Guesses: A form of Advertisement or Declaration of Intent.
T