I'm getting all Actions from a Trello Board using GET request to /1/boards/{boardId}/actions. I am getting JSON with all Actions, and some of them are of type updateCard (for example they describe changing title or a description of a Card). They specify what has been updated (e.g. was it description or a title) under position json['data']['old'].
My question is, does it always return only one value in json['data']['old'] or is it possible that, for example, both title and description of a Card were updated in the same action? According to my tests it is always one, however I'm not 100% sure. Thank you in advance.