Obtained via the FOIA faires. An internal Illinois State Police document details how the ISP interpret the law and just what "needs" to be registered so that one is not committing a crime (unlawful use of weapons) come 1/1/2024:
Yep! You read that correctly. In order to not be committing a felony in the eyes of the ISP, ALL ATTACHMENTS (this includes things like dust covers, grips, springs, stocks, extractors and all spare parts/add-ons you own for so-called "assault weapons") need to be itemized and submitted to the state police along with the guns that meet the banned criteria. So, that Magpul vfg you have laying around somewhere from 5 years ago? Better list it or you are "breaking the law" and the ISP views it no different than holding out (not registering) your scary black guns. That AR detent that flew across your living room and is lost? That's a "assault weapon" component and if not listed, you're, in the eyes of the ISP, committing a violation of this law. Here's what the law states is an "assault weapon attachment". Can you say "vague"?