Boop is the effect of Erfworld's built-in censorship, whereby Parson's profanity comes out as "boop" instead. One of the odder in-universe mechanics, this is discovered by Parson almost immediately after being summoned. While the Erfworld natives apparently understand the intentions of the word, Sizemore and Wanda are the only characters to have responded in a manner that implies they understand the specifics of each use. At the end of book one, Parson manages a curse that is conspicuously not booped out.Erf-b1-p150 This change may illustrate his developing transcendence of the Erfworld ruleset. This is compounded in the summer text update 009, where parson manages another curse word that is not booped out, though attention is not drawn to it.