Schema extension for SCIM 2.0
<p>We have an Identity Provider User registry, and a SOAP Web Service for applications to read/write user profiles. Now we plan to add a SCIM interface as well.</p>

<p>We find that Core User schema covers the basic set of attributes, however our existing system has a different naming convention for the same attributes.</p>

<p>For example, say USERTELEPHONENUMBER, USERSTREETADDR1 and so on.</p>

<p>Considering large number of applications already using this naming convention, we would like to continue the same with SCIM 2.0.</p>

<p>Given that we can extend the Core User schema, </p>

<p>1) Can we opt not using any attributes from Core schema ? If the payload includes these attributes, can we simply ignore them on the server side, and process only custom schema attributes ?</p>

<p>An example User document - </p>

<pre><code>    {
        "schemas":    [ "urn:scim:schemas:core:2.0:User",
                     urn:scim:schemas:extension:customattrs:2.0:User"], 
        "id": "2819c223-7f76-453a-919d-413861904646",

        "urn:scim:schemas:extension:customattrs:2.0:User": {
            "USERFIRSTNAME": "fname",
            "USERLASTNAME": "lname",
         "USERTELEPHONENUMBER": "1231231234
     }
    }
</code></pre>

<p>2) We can define a new resource itself and define a new core schema. </p>

<p>Which of these options would be a cleaner way ? </p>