All energies
Electricity comes to mind first but is not the only one: compressed air, hydraulics, steam, gas, spring tension, gravity and residual heat are energies too. An equipment-based procedure lists every source of that equipment one by one.
Lock and tag
Cutting is not enough; the cut point is locked and tagged. The tag says who locked it and why. Everyone has their own lock; one person opening another's lock removes the system entirely.
Verifying zero energy
After locking, that energy really is cut is tested: an attempted start, a measurement, a pressure release. Isolation not verified is not isolation.
Working as a team
Where more than one person works, each applies their own lock; the equipment cannot be energised until the last lock comes off. At shift change the handover is written.
In Optifora
The permit module lists isolation steps against the equipment, keeps lock holders on record, and will not close the permit until the verification step is marked.