And when you take a case to Tax Court, a revenue ruling (remember those?) has no special weight there because they are deemed merely to represent the contention of one litigating party. IRS silence on this issue indicates at least that there is no obvious answer.  I'll rely on an eventual IRS statement that MCTR is not taxable, whether more or less than $600.  If IRS says it's taxable and will be an issue in every California audit it conducts -- I'll be surprised.