After the whole Vine kerfuffle and Yandex situation, Facebook clearly feels it has some explaining to do. Over at the site's Developer Blog, director, platform partnerships and operations Justin Osofsky would like to set some things straight about the social network's platform policies. He begins by assuring developers that most can just keep on keeping on.
Osofky adds, however,
For a much smaller number of apps that are using Facebook to either replicate our functionality or bootstrap their growth in a way that creates little value for people on Facebook, such as not providing users an easy way to share back to Facebook, we've had policies against this that we are further clarifying today
Those developers (and interested civilians) who'd like to drill down a bit further into those newly clarified policies can check the fine print in the source link below.