Invalid Namespace Specific String: attribute

The SSSE requires that this attribute's value to conform to the syntax for Namespace Specific Strings (the NSS portion of a URN) in RFC 2141.

Consider replacing characters which are not in the allowed list with a % followed by two hex characters. If the character in question is not in the range allowed by the ASCII encoding, encode the string as utf-8 first, and then percent encode any octets not in the <trans> list.