base64Binary data type

For base64-encoded binary data, the entire binary stream is encoded by using the base64 alphabet. The base64 alphabet is described in RFC 2045.

The lexical form of xs:base64Binary is limited to the 65 characters of the base64 alphabet that is defined in RFC 2045. Valid characters include a-z, A-Z, 0-9, the plus sign (+), the forward slash (/), the equal sign (=), and the characters defined in XML 1.0 (Third Edition) as white space. No other characters are allowed.