replace angle brackets

Co-authored-by: Henrik Tidefelt <henrikt@wolfram.com>

chapters/packages.tex

@@ -421,9 +421,9 @@ \section{Multilingual Descriptions}\label{multilingual-descriptions}
 Note that if a \lstinline!msgid! string is given more than once in the same context, all occurrences are translated with the same (last) translation!
 
 The keyword \lstinline!msgstr! is followed by the translation of \lstinline!msgid!.
-With regard to control characters and line breaks, the same rules apply as for \lstinline!msgid!.
+With regard to control characters and line breaks, the same rules apply as for $\mathit{messageIdentifier}$.
 In the template file this string is empty by definition.
-If this is empty in a language specific file the contents of \lstinline!msgid! may be used instead.
+If this is empty in a language specific file the $\mathit{messageIdentifier}$ may be used instead.
 \end{nonnormative}
 
 The texts in following Modelica constructs should be translated: