label: Encoding as defined by MIME (Multipurpose Internet Mail Extensions) standard RFC 1521. Four consecutive ASCII characters represent three consecutive octets of binary data. Base64 utilizes a 65-character subset of US-ASCII, consisting of both the upper and
label_lc: encoding as defined by mime (multipurpose internet mail extensions) standard rfc 1521. four consecutive ascii characters represent three consecutive octets of binary data. base64 utilizes a 65-character subset of us-ascii, consisting of both the upper and