The T206 set is probably the most widely-collected of all the prewar baseball card issues, and the subject of an immense amount of scholarly analysis.  Such intense scrutiny has, over the years, revealed a number of interesting print variations that were the result of errors in the print process, due to mechanical or man-made errors like ink deficiencies, or damaged or obscured printing plates.  When a substantial enough of a given variation are noted, then collectors begin to consider it a legitimate error in the set.  

One such error is the "Red 8" variation on the Rube Marquard "follow through" card.  On some of those cards, a small, red number 8 can be seen on Marquard's shoulder.  Another example is the Fred Mitchell Toront/Toronto variation.  Another is the Red Murray/Murr'y variation.

Presented here is a more recently-discovered variation, of the Fred Pfeffer card that lists him with "Chicaco," rather than "Chicago."  Likely a result of a flaw in the printing plate obscuring part of the "G" in "Chicago," the variation would likely be recognized in the Standard Catalog (if there was one).  Currently, of the main grading companies, Beckett recognizes the variation.

Presented here is a collector-grade example, suffering from significant wear and spots of paper loss.  However, the variation in the type is clear, a desirable example for anyone looking to complete a T206 set with all errors accounted for.