What sort of paper is the Scotsman?

I wanted to buy a copy of the Scotsman in Heathrow this morning. Rather than picking it up from amongst the "mainstream" papers (which I assume would describe themselves as "British", not "English") I had to go and look for it amongst the "foreign" and foreign language papers. Is the Scotsman not a "British" newspaper then? I thought it described itself as "Scotland's national newspaper".