where to measure the midriff

I recently bought the Barcelona skirt pattern.  I am having a hard time deciding where to measure the midriff.  I am getting conflicting information on the search engine for google.  Am I right in my thought that the midriff is your waist measurement?

I’m going to qualify this by saying that I haven’t used the Barcelona Skirt pattern, but I suspect that “midriff” is being used in place of “waist” because you wouldn’t want to wear the skirt on your true waist – probably you want it a couple of inches lower.  I would put on a skirt with a “waistline” you like and take the midriff measurement around the top of that skirt.  Again, I haven't seen the pattern but, if the midriff measurement is meant to help you determine the circumference of the top of the skirt, I think they may be asking you to base it on where you want the skirt to sit, not your natural waistline. 

Thank you for your reply.  I will try that.