Any gains and losses can be offset at the financial year that...

Any gains and losses can be offset at the financial year that occurred during that FY.
Any losses from previous FY's can be carried forward indefinitely and be offset against future gains.

The second part I will leave to someone else.
I have a good idea but dont want to comment as I'm not 100% on it.
I think if you read back through this thread you will find your answer though.