What are the Health & Welfare guidelines?

I've had to revise my knowledge since coming to my new unit on Health & Welfare inspections. It seems soldiers DO NOT need to be present for the search, it's a unit discretion about their NCOs being present.
My questions are is the command required to give 24 hours (or any time) notice to the soldiers or NCO's prior to a full health & welfare? (This sounds odd to me too but an officer came and asked me so I am looking to verify an answer)
I have looked through FSBP 2020 // AR 420-1 Facilities Management // The ethics information paper published by Chief, Military Law and Ethics Division // and the DoD Manual for Housing Management
However I have found little guidance to directly lay out an Army wide standard of what can be expected for a H&W.
I know now that Commanders with JAGs assistance must direct the inspectors as to what they are looking for and where they can look.
o Soldiers must ALL have the same level of inspection.
o Commanders cannot search POVs that are not in the unit parking area.
o Commanders cannot search off post housing without a civilian police warrant.
o Commanders cannot execute a H&W because they think a soldier has illegal firearms or substances in place of a coordinated police effort for search & seizure.


Any extra help would be greatly appreciated so I know I am advising both my soldiers and leaders correctly.