Author/Illustrator/Editor FAIL

Apropos of the previous "Design Fail" post,

The Rockwell typeface: http://en.wikipedia.org/wiki/Rockwell_%28typeface%29 is a serif font. (Serifs being the little sticky-outy bits on various letters in fonts like Times New Roman and, say . . . ROCKWELL) No wishy-washy maybe-serifs about this one, those are big chunky ones.

But "Graphic Design for Non-Designers", Tony Seddon & Jane Waterhouse, illustratons by Rick Landers, 2009, Chronicle Books, ISBN: 978-0-8118-6831-0 calls it a sans-serif.