With national census clean-up efforts winding down, I don't think I'm telling any tales out of school to mention what I found to be the most difficult aspect of employment as an enumerator: the serifs on the letter I.
The correct way to fill out forms, according to the Enumerator Manual (from which these images are scanned) is with horizontal lines at the top and bottom of the I. It is, however, the only letter you print with serifs.
It made me nuts every time I had to do it. Which was often. It slowed me down, it hurt, it made my brain bleed. It looked terrible. It threw an immediate monkey wrench into the x-height you were maintaining in your head and awkwardly cramped down the "I," the letter buckling between the serifs like a vise. No serif - no serif - no serif - no seriffffffffff...oh no, SERIF. I need a cocktail. Bad, wrong, bad. WRONG. Regroup, start writing again--fuck. Another I. Misery. I believe at some point during training I actually raised my hand to complain about the serifs, in a fit of anguished design nerdery.
According to the Census the serifs are there for purposes of optical scanning, to distinguish it from the number 1, but I suspect lazy reasoning there. Why are there no O/0 problems then? There has to be some contextual reading to distinguish those. So why burden your poor employees with the agonies of the extra lines? Sigh.