Economy V2 FriendlyId forbidden characters

Hello!

Asking here since I couldn't find any documentation on this.

Is there any set of forbidden characters for an item's FriendlyId ?

I get a 500 error when trying to create one with a colon character ':'

POST https://{ {TitleId}}.playfabapi.com/Catalog/CreateDraftItem, body:

 {
     "Publish": true,
     "Item": {
         "AlternateIds": [
             {
                 "Type": "FriendlyId",
                 "Value": "a:1"
             }
         ],
         "Title": {
             "NEUTRAL": "some-title"
         },
         "Type": "catalogItem"
     }
 }

Since other special chars that I tested ['!', '@', '_'] work fine I assume this is an error and it will get fixed?