In constructing a message, certain special characters are used. They are the segment terminator,
the field separator, the component separator, subcomponent separator, repetition separator, and
escape character. The segment terminator is always a carriage return (in ASCII, a hex 0D). The
other delimiters are defined in the MSH segment, with the field delimiter in the 4th character
position, and the other delimiters occurring as in the field called Encoding Characters, which is
the first field after the segment ID. The delimiter values used in the MSH segment are the
delimiter values used throughout the entire message. In the absence of other considerations, HL7
strongly recommends the suggested values found in Figure 11.