10. A system for embedding metadata with displayable data, comprising: a message ID encoder that encodes the metadata into a sequence of non-displayable characters; a message combiner that combines displayable data and the sequence of non-displayable characters; and a server, implemented on at least one computer, that sends the combined displayable data and sequence of non-displayable characters to a client; wherein the message ID encoder comprises: a binary converter that converts the metadata into a binary number; and a Unicode converter that maps each digit of the binary number to a non-displayable Unicode character, and wherein the displayable data includes a sequence of displayable Unicode characters.
10. A system for embedding metadata with displayable data, comprising: a message ID encoder that encodes the metadata into a sequence of non-displayable characters; a message combiner that combines displayable data and the sequence of non-displayable characters; and a server, implemented on at least one computer, that sends the combined displayable data and sequence of non-displayable characters to a client; wherein the message ID encoder comprises: a binary converter that converts the metadata into a binary number; and a Unicode converter that maps each digit of the binary number to a non-displayable Unicode character, and wherein the displayable data includes a sequence of displayable Unicode characters. 11. The system of claim 10 , wherein the Unicode converter maps each digit of the binary number to either a left-to-right mark (0x200E) or a right-to-left mark (0x200F).