The library preserves observations, measurements and changed conditions when the source contains them, while keeping professional-risk procedures behind a clear safety boundary.
The same symptom can have a different cause. Stronger evidence reduces guesswork but does not make one case universally transferable.
The public case pages do not turn technician discussions into homeowner instructions for live voltage, gas, refrigerant, microwave high voltage or energized moving parts. They explain the reasoning and the evidence boundary instead.