Question: What specific encoding rule is applied to the Network Access Identifier (NAI) when storing the IMS Private User Identity in the EFIMPI on an ISIM application?
Option 1: ASCII Encoding with a fixed length of 16 bytes
Option 2: URL Encoding as per W3C Recommendations
Option 3: Base64 Encoding for binary data representation
Option 4: UTF-8 Encoding as specified by IETF RFC 3629
Explanation: The correct answer is Option 4 because the NAI shall be encoded to an octet string using UTF-8 encoding rules, ensuring compatibility and proper interpretation of the private user identity across different systems, particularly suitable for diverse user identities due to its wide character support.