This guide covers sex offense charges and registration obligations systematically, from the substantive offenses through classification, restrictions, and the narrow paths to relief. The opening parts cover the federal offenses and the recurring state charge structures that generate registration, together with the procedural features — rape shield rules, prior-acts evidence, child witness accommodations, and digital forensics — that distinguish these prosecutions, and then the constitutional framework treating registration as civil regulation, the retroactivity holding that follows from it, and the state constitutional litigation that has diverged from it. The middle parts cover the federal SORNA framework and the state systems that actually administer registration, how classification is assigned under offense-based and risk-based models, and the operational detail of registration itself — initial registration, verification intervals, and the reportable events that generate most failure-to-register prosecutions. Later parts cover residency, presence, employment, and internet restrictions, then community notification, civil commitment, and juvenile registration. A dedicated part covers plea negotiation, which is the only stage at which the registration consequence is negotiable, with the analysis to run for every candidate charge. The final part covers termination, tier reduction, relocation, and the record a relief petition requires. Tables, checklists, and worked examples appear throughout.