JIRA 6.3 will introduce the ability to create issues "inline" while you are in plan or work mode on a board. This feature is designed to help you quickly add issues to a sprint or backlog by adding a minimum amount of information and without leaving the board.
You can optionally add more details to the issue without leaving the context of the board, or you can continue to create issues to fill out a backlog or sprint.
When you create a new issue using this feature, JIRA pre-sets many of the issue settings based on the board where the issue is created, default project settings, and other data. For example, JIRA might automatically set the Reporter (as the user creating the issue), the Epic (as defined by the JQL for the board), and the Priority (as the default issue priority). You can override any of these pre-filled settings by clicking to open the Create Issue dialog.
If the JQL associated with a board is too complex for JIRA to determine certain information or there isn't enough information for JIRA to determine the setting for a field, it leaves those fields blank. (For example, if the board includes issues from multiple projects, JIRA can't determine which project to place the issue in.)
JIRA admins can disable this feature from the JIRA administration settings.