(Sorry everyone we are temporarily hijacking this thread...)
If you really can't pay and you can provide documentation to prove it, they will waive the fee or let you pay it in installments. If you just refuse to pay it, they will still let your child attend school. However they will not give out any report cards or release transcripts to any colleges or jobs until you settle up. It's absolute garbage, but most of us pay it rather than fight it, because refusing to pay it only hurts the schools, and they are already broke. They people making us pay the fee (school board, city of Chicago) couldn't care less if we actually pay it because it doesn't go to them. And they cut the budgets so much that the schools desperately need it.
I home schooled my older daughter because the schools in Chicago are the worst I've ever seen. They're a joke in every aspect. My younger daughter is fortunate enough to have been accepted into a gifted school and it is run very differently from the rest of the city schools. Financially it is also a disaster, but at least in her case we're getting something back out of it (a good education). Her selection of high schools to choose from will also be drastically different from what 99% of kids in Chicago have to choose from.
I really don't know how the powers-that-be here sleep at night. :(