Originally Posted by patrickw

I am assuming your destination is in Australia since the tax code for WY/AU are used by arrival/ departure taxes Australia. The oneway K fare (KLAROSW8) from ZRH to Australia seems to be CHF741 (from ITA Matrix) so it is basically same as the fare you have paid.

The other parts of refund include roughly half of the YQ (~CHF175), Australia departure tax (Coded AU CHF41.35), half of the Hong Kong Airport Construction Fee (G3) which is around 20CHF, and half of the Hong Kong Airport Passenger Security Charge (I5) which is around 6CHF. After adding up these components and take out the cancellation fee of 150 CHF will give you roughly 100CHF. I hope it gives you the idea how the 100CHF is determined.