\def\delayedwriteid#1#2{\write\ids{\string\iddef{#1}{#2}{\refcurrentfile}}}
% Used in auxiliary files
-\def\iddef#1#2#3{\ifcsname id:#1\endcsname\immediate\write16{*** Warning: Identifier #1 re-defined ***}\else
+\def\iddef#1#2#3{\ifcsname id:#1\endcsname\ucwwarn{Identifier #1 re-defined}\else
\expandafter\def\csname id:#1\endcsname{#2}%
\expandafter\def\csname ff:#1\endcsname{#3}%
\fi}