Selfconfusing code

Sigh, going through one of our more complex, rarely edited sourcefiles at work, I came across this line:

j=i+19

I have a reasonably good grasp of what i is. j seems to have very little relation to anything, and I have absolutely no clue what the 19 is. 19 what?

Developers out there, for my sake, if you don’t already, please start using meaningful variable names, and hey, I wouldn’t mind a few constants on occasion.