Limiting Value list

[panchristo]

I know I have found once a topic about this but can't find it again:

How can you limit the available values from a list in order to prevent duplicates?

I would like to use this in a field (person ID) using a value list inside a portal where I select the name of a person but hide it afterwards in such a way that the next related record will be impossible to have the same person ID.

[panchristo]

Answer has been found here , moderators please lock the subject.