\vspace{}
\vspace*{}
\whiledo{}{}
-\xymatrix{} % this is basically an array => the contents would be parsed badly (bug 8396)
% LaTeX environments.
% They have always one extra "argument":
math{}
displaymath{displaymath}
flalign{displaymath}
-flalign{displaymath}
+flalign*{displaymath}
% These require extra args
alignat{}{displaymath}
alignat*{displaymath}