Tending my Garden til 6/2020
As Thornback correctly describes, the DOFD is the date of the first delinquency in the chain of delinquency, and is "reset" when an account is brought into good standing, and thereafter a new chain has a new first delinquency.
The DOFD sets, under FCRA 605(c), the begin of the exclusion period for a reported charge-off or collectionm and applies to reported collections or charge-offs.
If no CO or collection is reported in a first chain of delinquency, and the debt is brought back into good standing, if a new chain of delinquency then occurs that results in reporting of a CO or collection, that new (later) DOFD is the begin date of the exclusion period, and not the prior DOFD.
However, if a CO or collection was reported under the first chain of delinquency, the DOFD for that period still applies to the exclusion of a CO or collection that occured during that first period of delinquency.
While it is very rare for an account to remain open after a CO or collection, and thus subject to a second period of delinquency if the debt is than paid, it is theoretically possible, particularly for an installment loan..
Thus, in the very rare but possible scenario where a delinquent account that was charged-off or a collection reported under the first period of delinquency, and then remained open in good standing and was subsequently subject to a second CO or collection, there could be two relevant DOFDs, each applicable to its own separate period of delinquency.