Final answer:
The tag that is used to lock out and tag potentially hazardous energy sources should read 'DO NOT OPERATE'.
Step-by-step explanation:
In this situation, the tag that is used to lock out and tag potentially hazardous energy sources should read 'DO NOT OPERATE'. This tag is typically used to communicate that the equipment or machinery being serviced or repaired should not be turned on or operated until the tag is removed by the authorized individual.