Things you shouldn't do

[Paul McGuire]

This struck me also when I first saw this post.  It reminded me of a
body of code I inherited at a former job, that I had to help untangle.
The code was filled with two key variables: t_1 and t_l.  Printing out
the source in a Courier font made these two vars completely
indistinguishable, and it took a while to realize that there even were
two different vars.  After globally replacing them with t_first and
t_last, things became a lot clearer!

-- Paul