Merge pull request #2544 from otronarp/MCP/0033-clarify-identifier-un…

…iqueness

Clarify the uniqueness of Figure and Plot identifiers

chapters/annotations.tex

@@ -114,12 +114,16 @@ \subsection{Annotations for Figures\doublelabel{annotations-for-figures}}
 replacements, as described in \autoref{variable-replacements}, can be used in the
 \lstinline!title! of \lstinline!Figure! and \lstinline!Plot!.
 
-The \lstinline!identifier! in \lstinline!Figure! and \lstinline!Plot! is
-optional, and is intended for programmatic access.  A \lstinline!Figure!
-\lstinline!identifier! must be unique within the class containing the
-\lstinline!figures! annotation, whereas a \lstinline!Plot!
-\lstinline!identifier! must be unique among the \lstinline!plots! in the
-\lstinline!Figure! annotation.
+The \lstinline!identifier! in \lstinline!Figure! and \lstinline!Plot! is an
+optional \lstinline!String! identifier, and is intended to identify the
+\lstinline!Figure! and \lstinline!Plot! for programmatic access.  A
+\lstinline!Figure! must be uniquely identified by its \lstinline!identifier! and
+containing class.  This means that a \lstinline!Figure! \lstinline!identifier!
+must be unique among all \lstinline!Figure! annotations within the same
+\lstinline!figures! annotation as well as among all \lstinline!figures!
+annotations from inherited classes.  A \lstinline!Plot! \lstinline!identifier!
+on the otherhand is only required to be unique among the \lstinline!plots! in
+the the same \lstinline!Figure! annotation.
 
 \begin{nonnormative}
 For \lstinline!Figure!, this makes it possible to reference the plot from a