Feature Request: credits in galleries

While it’s possible to do, the feature would have to work via the gallery shortcode filter. Unfortunately, that means it would be very easy to break as a lot of plugins override the gallery markup. I’m kind of reluctant to tackle something like this at the moment, as Gutenberg is just around the corner and will necessitate a large rewrite to support blocks. (Currently, galleries are implemented as a shortcode, which, while not officially deprecated, is a technological dead-end. There are several tickets for fixing bugs in the current implementation, but they have gone nowhere in a long time and the proposed ShortCake integration has stalled completely.)