Machine language time code
The Machine language time code or simply the time code is a code appearing in a tattoo on Fry's butt.
The code appearing in the film is as follows;
001100 010010 011110 100001 101101 110011
As you can tell, it is mirrored over the first three columns over to the last three and inverted over the first two rows to the last three. If you remove the last three columns, you can tell that the first three columns are actually just the numbers 1 to 6 in binary.
According to the commentary, it was originally intended to be the lottery numbers from some point in 2000. But it was supposed to be mirrored when Fry read it on his butt.