Field help (ISSDATRUL2) 

This field is used to select the issue rule to apply to the assets to renew.
Only the rules: On the specified day and No charge for the issue date are applied to the caducity plan. When another issue rule is selected, this rule will be applied on every plan except the Caducity plan, on which the On the specified date rule will be applied.
The issue terms applied are equal to the disposal's
For each modification of this rule, the funds forwarded by the assets to renew are recalculated.