lol. That’s funny!!
You obviously can make up any class name - there’s no semantics involved in a class name, just the tag. I don’t think there are any issues with copyright either… you aren’t really supposed to be able to copyright a language. The only thing I’m familiar with is people making a trademark (TM)… and it’s up to them to enforce it…. I would be surprised if anyone actually opened up your book to see what class names you use!!
You could use a generic <em> to emphasize the word/phrase, or even add a class to that if you wish:
<em class="brainism">
<p class="brainism"> for the whole paragraph
<div class="brainism"> for a whole section
CSS:
.brainism {color:grey-matter; font-family
siwave } /*or whatever you want*/
While typing it up you could use a simple "BI" and then find/replace at the end to whatever class name you come up with.