The pool value can be subject to adjustments. An adjustment could happen under foreign exchange (forex) rules that apply to transactions conducted in foreign currency.
If during the income year you met or otherwise ceased to have an obligation to pay in a foreign currency a project amount which you allocated to a project pool, you might have derived a gain or incurred a loss under these rules. If the amount in foreign currency became due for payment within 12 months after the time you incurred it, usually the pool value will be reduced by any such gain (known as a forex gain) and it will be increased by any such loss (known as a forex loss).
If the forex gain exceeds the pool value, the pool value is reduced to zero and the residual gain is assessable income which you should include at Other income. If you had previously elected that this treatment (known as 'the 12-month rule') should not apply, any gain will be assessable and should be included at Other income and any loss will be deductible and should be included at Other deductions.
For more information about the forex rules, see: Foreign exchange gains and losses.These myTax 2018 instructions are about deductions for certain capital expenditure allocated to a project pool.