Enum list

[akafester]

I was wondering if you could get the enum list to remove, or gray out, selections that has been selected elsewhere.
For example:
I have a shelf with 4 places that I have called 1 to 4.
On shelf place 2 I place an item, and in Espo I have a field that represent that place with the help of a Enum dropdown, and select 2 in that.
Now in another task, or whatever, I have another item which I want to place on my shelf, 2 is in use but the enum doesn't show that.

[tanya]

if it is selected in current record, you could catch this.
If not, it will be harder. Here better is to use an entity for shelf. And filter shelf, if they have no item on them.