# TikZ: Labeling objects and referencing them

According to the TikZ manual I can use name= to assign a label to the drawings, but when I do the following:

\begin{tikzpicture}
\draw [ blue, thick, name=e1]  (10pt,10pt)  ellipse   (50pt and 30pt);
\node (red,above) at (e1.north) {E1};
\end{tikzpicture}


I get an error message that e1 is not defined. What am I doing wrong?

My second question is where can I find a concise syntactical representation of TikZ's commands?

-

You can only name nodes, not arbitrary parts of a drawing. In your example, if you wanted to be able to refer to the ellipse by name, you'd need to create it as a node instead of a plain ellipse. Try replacing your \draw command with this:
\node[draw=blue,ellipse,name=e1,minimum width=100pt,minimum height=60pt] at (10pt,10pt) {};