Readium User Fields Registry
| Name | Value | Format | Required? | 
|---|---|---|---|
id | 
      Unique identifier for the User at a specific Provider | String | No, but highly recommended | 
email | 
      The User’s e-mail address | String | No | 
name | 
      The User’s name | String | No | 
encrypted | 
      A list of which user object values are encrypted in this License Document | Array of one or more strings matching the above names or an extension | Yes, if encryption is used for any field |