In uniPaaS I have a model (*Attribute=Alpha*; *Picture=1*) with *Range=J,N*. 
That allows the users to insert only J or N into an edit field using that model.
But now I have to change the range property of that model, so that a user also can type a space to that input field. Also it should be possible to leave the input field empty. 

I tried the following as Range, but nothing works:

```
J,,N
J, ,N
J,' ',N
J," ",N

```