Q1: Why does cryptox use XBT code for Bitcoin instead of BTC?
A1: Bitcoin has not yet been ratified by the International Organization for Standardization. We choose to use a code that complies with ISO 4217 standard for currencies.
Read more at https://en.bitcoin.it/wiki/Bitcoin_symbol
If you would like to know more about ISO 4217 standard click here: http://en.wikipedia.org/wiki/ISO_4217