Actually it's an “informal discussion letter” from the EEOC that standard criteria used for screening individuals needs to be “job-related for the position in question and consistent with business necessity.”

They go on to say that such a requirement could discriminate against someone who's disability prevents them from getting a diploma.

In other words, in non RWWJ speak, if being a dishwasher doesn't require a high school diploma then don't make it a criteria for being a dishwasher or someone might successfully sue you.