doc: Add note on expandsion of path operations #966

doc/generic/pgf/text-en/pgfmanual-en-tikz-paths.tex

@@ -94,6 +94,11 @@ \section{Syntax for Path Specifications}
     the path options (like filling and drawing the path due to a |fill| and a
     |draw| option somewhere in the \meta{specification}), the nodes are added
     in a post-processing step.
+
+    \emph{Note:} When scanning for path operations \tikzname\ expands tokens
+    looking for valid path operations. This however implies that the expansion
+    has to be fully expandable up to the point where it results in a valid path
+    operation.
 \end{command}
 
 \begin{key}{/tikz/name=\meta{path name}}