Post balance sheet events have a significant effect on the values shown in the accounts, and occur after the balance sheet date but prior to the date on which the accounts are approved by the directors.
Some of those events make more information available rather than altering the numbers as such. These are called adjusting events. An example of such an event is a sale of a fixed asset when the sales is agreed during the financial period but the final price is agreed after the end of the period. The final price will be reflected in the balance sheet and the P & L.
If a post balance sheet event is not an adjusting event but it is material, then it should be disclosed separately in the results.