iNTERFACEWARE™ Inc.

Troubleshooting

One very common issue that can occur when converting HL7 to XML and back again is how to correctly treat the '&' character that normally appears in the header of an HL7 message.

The '&' character is an escape character in XML and is used to represent XML entities. XML entities are used to represent special characters like '<' and '>' (represented as &lt; and &gt; respectively). Since the & character is a special character itself, it needs to also be escaped with the sequence &amp;. For this reason having a sequence like <MSH.2>^~\&</MSH.2> is illegal. The ampersand character must be escaped as follows: <MSH.2>^~\&amp;</MSH.2>.