http://bocpages.org/wiki/Cosecha_Transmisiones^This explains it pretty thoroughly, maybe a bit difficult to follow though.
Basically, there was an ad campaign leading up to the release of the most recent Boards of Canada album. Thought I'd share because I got so stoked when clues started popping up haha. I remember making a thread very similar to this one but about that album.
First there was a mysterious record released on record store day with a clue, then an advertisement on Adult Swim, then a clue on BBC Radio One, a clue hidden in the source code of a Boards of Canada fan page, and a final clue was projected at a record store. Each clue contained a 6 digit code, and when the codes were put together you could use them as a password to access the pre-order website for the album. Can't remember the last time I was so stoked for anything in my life haha.