How to read the source list
Each guide lists the sources supporting its most important factual statements. We favor official agencies, licensing authorities, public programs, standards, and manufacturer instructions appropriate to the exact context.
The scope note explains what a source can support and where it stops. For a provider, property, vehicle, patient, or facility decision, verify the current record directly.
Current source pack
- 811 Before You DigCommon Ground Alliance
Utility-location education before excavation; not a substitute for local permits.
- Trenching and excavation safetyOccupational Safety and Health Administration
Professional worksite safety and a strict no-entry boundary for homeowners.
- Department of BuildingsCity of Chicago
Starting point for current Chicago permits and inspections.