avoid repetition of an element

[MBdip]

hello all,
I have a list with several elements including user name and link.
Each user can enter your user name and its own link
but the problem is that each user can enter their user name as many times as he wants! Is it possible to allow users to enter their name in the list only once?

 

[troester]

You can add validations to any element, in your case use "isunique".

 

[MBdip]

how? I can see only this:

 

[felixkat]

You are in the right place but it looks like you don't have some of your validations enabled. These are plugins in the backend so you will need to enable them there.

They should be included on the default install so they should be there.

 

[MBdip]

You are in the right place but it looks like you don't have some of your validations enabled. These are plugins in the backend so you will need to enable them there.

They should be included on the default install so they should be there.

thanks a lot! it was in "manage exstention - > discover"