When a filter with consequences enabled is triggered by an edit, we show lots of different types of warning depending on the user action and the consequence itself. For instance:

1. For "edit" we show a red errorbox above the editing form. Such box contains one or more messages, depending on the combination of actions, and such messages may be in a bulleted list. As a side note, such errorbox isn't optimal at all due to text color (T187072)
2. For "move", we show a similar errorbox which also contains the text "You do not have permission to move this page, for the following reason" since the used hook is meant to check for permissions (T65768)
3. For "delete", the user is redirected to a page with title "Cannot delete page "<pagename>"", and its content is the parsed error message "as it is", i.e. not wrapped nor appended to other text.
4. For "createaccount", whe show an errorbox similar to (1.) above the signup form, reduced in width and with the same color issue as (1.).

I think we should uniform all these cases in order to have consistent behaviour and be able to foresee how the message will be shown.