hedging

in the article hedge accounting. it states new proposals- it uses rules based approached which argued that it is too complex. then it goes on about principle based approach stating that we need to classify cashflow and FV hedge. why is it difficult to distinguish cashflow and FV hedge?

does IAS 39 allows hedge to be optional?

it then gives an example in the article in acca website.

“IAS 39 allows hedge accounting to be optional. Therefore, even if a company does actually hedge and complies with the current rules they do not need to apply hedge accounting. The rules-based approach to hedge accounting also results in some companies who do hedge not being able to apply hedge accounting because they fall foul of the rules. An example of this is the inability to apply hedge accounting for specific components of non-financial items. For example an airline wishing to protect itself from changes in aircraft fuel prices can in reality do so by entering into forward crude oil contracts. This is because crude oil is a major component of aircraft fuel and the price of aircraft fuel will be closely correlated to crude oil prices. However, this is not considered a valid hedge under IAS 39 as the company can only account for a hedge of either the foreign currency risk, or the entire non-financial item (the purchase price of the aircraft fuel).”

I don’t understand this.