Ability to Require Unique Field Value?

In MIGX 2.5.9 / MODx 2.2.10, is it possible to enforce this type of validation in a migx tv config? If so, how? I've got a simple image chooser with only an id (used for a figure # [i.e., "Figure 1"]), an image title, and the image itself. The ID needs to be unique. [ed. note: smg6511v2 last edited this post 12 years, 10 months ago.]

every MIGX - item has 'MIGX_id' as a unique id.
You can get it with in the frontend

I did catch the MIGX_id when I inspected the json saved to the db. While that could be used in this particular use-case, it wouldn't be ideal for a number of reasons:

• When you drag/drop to change the order of items, the IDs do not get re-ordered
• You can't have a sequencing convention other than a straight numeric one (e.g., what if you wanted "Figure 1a", "Figure 1b", "Figure 2",etc.?)
• You can't begin your sequence with a number other than "1"

I suppose the ultimate question I'm asking is whether any kind of validation is available in a migx-based tv and, if so, what are the methods for specifying various validations?