Clarifying the standards and procedures for determining whether a government agency is justified in rejecting a categorical request for documents as unduly burdensome under Section 3(g) of the Illinois Freedom of Information Act, the appellate court affirmed an order that granted the Chicago Board of Education’s motion to dismiss a complaint filed by the Sargent Shriver National Center on Poverty Law — although the 1st District rejected the board’s argument that it did not have to prove by clear-and …