As Timothy said, there are many threads on BIB
Here's a little more information about "Bonded"
At Heaven Hill, there a marks on the floor where partitions "used" to be. When "Bonded" (BIB) product was bottled, the line was sectioned off and no one crossed that line. Only the government men, and line help were allowed to handle the product. There's a term used in a BIB back label. Bottled in Bond under U.S. Government Supervision...Today, the government men, pop in (at random) form time to time. Almost all the supervision is in paper form. BIB product is stored in a section of it's own in the warehouse.
The government men had a tight hold on distilleries back then. HH's government man was Paul Civils (Paul's son---Dave---sill works at HH

)...Paul, had the key to unlock the warehouses, tanks etc. Heaven Hill did not run until the "government man" was there to unlock the product

If the government man was late for work...Heaven Hill ran late that day too.
Still to this day, all employee's (me included

) have to be bonded to handle all spirits at Heaven Hill.
Bettye Jo