Trying to book flights on the star website - what a nightmare - what on earth does RUC on the page where you fill in credit card details mean? Or Razon Social - the booking site is this weird hybrid of english and spanish. It's making my head hurt. It says I can pick the tix up 2 hours before departure - does that mean not after that or up to that? Anyone any experience?

Oh good grief - I thought, what the hey, all the credit card details are in there - I'll see if it goes through without the two mystery boxes filled in - AND THE SITE FOLDED IN ON ITSELF AND CRASHED. I have no idea if the booking was made, anything.
I have tried to look up the two phrases I asked about to no success.

Which country is this? RUC in Bolivia was a tax number (which was replaced by NIT in 2005), and other countries in SA may use the term RUC - looks like Ecuador does, although I'm not sure if the meaning is the same. Razón Social means business/corporate name.
I would guess that neither apply to you, although whether they will sell tickets to people without this information is another matter...

Thanks Benjus - do appreciate it. It remains to be seen if I've booked seats Lima to Cuzco or not - I've emailed them, just hope they get back to me soon... as need to book if not. Oh well. At this rate it'll be a nice peaceful flight as I'll have booked out half the plane...
A well designed online form would change its requirements if you choose your country of procedence/residence at the beginning, and would not ask you for RUC (tax number) and Razón Social in Perú. But Star website seems to have been poorly designed. It can not even work if you use Mozilla Firefox or similar browsers. It is the cheapest airline in Peru, but to get a better online service, you could maybe try TACA or Aerocondor.