Bitcoin is not called BC.

If there is no official abbreviation, that does not mean calling it BCT is also correct.

It can be called BTT. But depending on what that is official.

Before I know this forum, I saw it abbreviated as BTT on another r forum that I was.

People that I know are calling it BTT until yesterday that some people said it can be called BCT.

I will choose BTT as bitc oin is called BTC.