kayakamina, it is a Rainbow quiz issued twice a year either by post or on the internet (I believe. Googling Rainbow Quiz should give it to you.) Each quiz supports a different charity and you pay a minimum of �1 entrance fee, with small prizes for those who get full marks (100), of which there are always a lot, the winners having to be drawn from a hat.
But the honour is getting 100 questions right which consist of sometimes very difficult cryptic clues. There are no 'checkies' as in a crossword puzzle but they do all relate to one theme connected with the charity concerned.
Sadly, the kudos of getting 100 is not as great as it used to be because so many people get their answers from others on this site. But there you are - what does it matter as long as the charity is supported?
Puzzles come out at end of Feb (to be completed by end of May) and end of August (completion end of November).