Lp1?

you mean on the mint wrapping? the actual coin does not have a mintmark

It used to be that none of the Philly coins had mint marks. It was until the 80s that Philly nickels, dimes, quarters, halves and dollar started carrying them. They never changed the cent to keep with tradition or something.

It is my understanding that they did this to prevent the hoarding of cents that were minted in San Francisco and/or West Point during the 80's (and possibly later, I am not sure).

Since those mints produced lower numbers (to supplement the Denver and Philadelphia production) they omitted the mint marks to keep them from being collected out of circulation.

A lie? No, an omission.

Edit: I found in this post that West Point made cents from 1974 to 1985.