When you are officially accepted into the program it will be for one specific region who will, from then on, be the branch of government responsible for you. You are then given two choices: accept or reject. Should you accept, it is then taken that you will be participating in the region that you were accepted into. To be clear: If you don't accept the region you are given, no dice.
I know that in past years, there was some swapping. However, I will tell you that it seems as if things are getting stricter as this program gets older. In the past, there were folks repeating this program up to four times. However, from what I have seen now it looks as if people aren't even going to be able to return for a third year.
I feel like I've heard that last year you were only allowed to swap within the region you were assigned.
I was wondering, though, is it possible to change your preferences (or anything else about your application) after you submit your online application (but before assignments begin to be made)?
Not that I want to change mine... it's Madrid or die for me anyway!
These are the preference categories by "grupo", it seems the groups are categorized by popularilty, basically requiring everyone to choose a less popular destination as their third choice. Seems like they were trying to trick us by putting the least popular destinations in "group A"
Grupo A:
Asturias, Ceuta y Melilla, Extremadura, La Rioja, Navarra, Pais Vasco
Grupo B:
Aragón, Cantabria, Castilla la Mancha, Cataluña, Galicia, Islas Canarias
Grupo C:
Andalucia, Castilla Leon, Islas Baleares, Madrid, Murcia, Valencia