Document duplicate header behavior #309

Author: garydgregory

src/changes/changes.xml

@@ -43,6 +43,7 @@
     <release version="1.10.1" date="2023-MM-DD" description="Feature and bug fix release (Java 8)">
       <!-- FIX -->
       <action issue="CSV-306" type="fix" dev="ggregory" due-to="Sam Ng, Bruno P. Kinoshita">Replace deprecated method in user guide, update external link #324, #325.</action>
+      <action type="fix" dev="ggregory" due-to="Seth Falco, Bruno P. Kinoshita">Document duplicate header behavior #309.</action>
       <!-- UPDATE -->
       <action type="update" dev="ggregory" due-to="Gary Gregory">Bump commons-io:commons-io: from 2.11.0 to 2.13.0.</action>
       <action type="update" dev="ggregory" due-to="Gary Gregory">Bump commons-parent from 57 to 58.</action>