On many photo contest rules, we find the condition that photos must be unpublished to take part on them. That was quite a simple rule when our only way to show our work on public was trough exhibitons and traditional media, like magazines, newspapers, etc. But now, we constantly upload our photos to Instagram, Twitter, Facebook, and so on. Does that fit into the traditional meaning of "published", meaning that these photos won't be allowed to take part on such a contest?
In practice: suppose I uploaded a picture to a public instagram account. Some time later, I hear about a contest and think that photograph would be appropiate for it. Rules specify that pictures must be unpublished. Should I:
a - Assume that "unpublished" refers to traditional media, so my picture can take part on the contest?
b - Resign about sendig that photo to the contest, as it would be understood as a "published" one?
c - Delete the picture from my instagram account and then sending it to to the contest, assuming that the rule doesn't apply at previous publications which have been deleted?
I'm aware this might vary from one event to another, and depend on national laws. I'm asking about general tendencies in international contests.