The Ghirardelli web site says

"Bittersweet chocolate often has an unsweetened chocolate content of 50%
or more."
http://www.ghirardelli.com/chocolate_types.html

They seem to always indicate percentages as % of "unsweetened
chocolate", which I take it is processed nibs, but does not include the
cocoa butter.

Most chocolates indicate a % minimum "cocoa solids", is this the same
thing? ie. not including the cocoa butter?

If so, I'm surprised that Ghirardelli would indicate that 50% is the cut
off for semi-sweet vs. bittersweet chocolate, cause I would have thought
it was more like 60%. I'm also surprised that their 'semi-sweet'
chocolate bar is 35-45% - that seems quite low to me.

Tom.