@stof I agree that it doesn't make sense, I just wasn't aware that Composer worked that way.

In that case, we *could* simply use `~2`. You are right saying that it doesn't make sense to allow 2.0 or 2.1 
if your application is not compatible with it, but in this case we're talking about a new application. (and 2.0 wil actually not be a problem as the lowest release on packagist is 2.1.0)

The problem with specifying a minor version is of course that every time a new minor version is released, this documentation needs to be updated.

So, what would you suggest? Using the broader `~2` or the more specific `~2.3` or `~2.4`?