You are right. Its just a normal validation with "values from" and "existing values only" tag. It the first message of this thread, I described the situations when current implantation doesn't work correctly (the same situation described in bug),

So, I was working on patch, which a) solves this problem b) add "existing values only" to  "text with autocomplete". Actually, I am going to make some changes in this patch and provide it again.

On Wed, May 30, 2012 at 4:28 PM, Stephan Gambke <s7eph4n@gmail.com> wrote:
I read the bug and the thread. I still do not understand what
"one-to-many" validation means. What do you want to validate against
what? What is the "one", what is the "many"? How would it be different
from normal validation?

On 30 May 2012 11:22, Vladimir Kostyukov <vladimir.kostukov@gmail.com> wrote:
> I guess, its about SematicForms. You can read this thread. Here is bug about
> it  https://bugzilla.wikimedia.org/show_bug.cgi?id=32976. Also you can read
> current
> thread: http://wikimedia.7.n6.nabble.com/quot-one-to-many-quot-validation-td678004.html#a1572068



--
Thanks,
Vladimir Kostyukov