Suppose I want to reuse some substantial piece of content - say, a figure1 - from someone else's paper in my own scholarly work. If the other paper is under a traditional license, I'll have to obtain explicit permission from the copyright holder (usually the publisher), and then when I include the figure in my own work, I can say "Figure from reference [x], used with permission."
However, if the other paper is under an open access license or is in the public domain, and my own work will be released under a compatible license, I don't need to explicitly contact the copyright holder to ask for permission to use their content. When I attribute the figure in my work, can I still say "used with permission"? Legally speaking, I do have permission to use it by virtue of the license under which it is released (or lack thereof, if public domain), but including that phrase makes it sound like I've received an explicit statement of permission from the copyright holder, and I wouldn't want to give a misleading impression about that.
If I shouldn't say "used with permission," what would be a suitable replacement? If it's under a Creative Commons license, for example, I could say something like
Figure from reference [x], used under the terms of the Creative Commons Attribution 4.0 license
but that seems a little verbose. Is there a better alternative?
I'm also interested in how to handle this when the content is in the public domain, or is under a much more permissive open access license (perhaps one whose attribution requirement is merely "you must credit the author"). I understand that I'm not legally required to include any notice saying that I'm allowed to use content under such a license. But for this question I'm more interested in the ethical obligations that a reader might perceive.
1Even though a single figure would often be considered fair use. But let's pretend for this question that whatever I want to reuse is enough that fair use doesn't apply.
This question concerns a similar situation, but is asking about whether it is legal to reuse content at all, whereas I'm asking about how to properly show that it is legal to do so, after it's been established that no explicit permission is necessary.