Don't really know how someone would declare Bitcoin Cash, it can be qualified as dividends from bitcoin or even as a donation or gift.
Luckily my goverment still forbid bitcoin usage so I can use bitcoin without pay any tax
IMO, even if my goverment one day legalize bitcoin usage, they must not applied tax on bitcoin since bitcoin basically is not a currency but it's a virtual currency
Let's think for a moment about what this means. Bitcoin and similar convertible virtual currencies are property for tax purposes. As with other types of property, first one acquires property, often by exchanging cash for the property. Then one owns the property for a period of time. And then eventually one might sell or give away or trade or otherwise dispose of the property. So with any type of property we have three moments in time: acquiring the property, holding the property, and disposing of the property.
While in some countries the situation is different. They treated biycoin as a legal and regular currency and has the rules as for paper currency.