Index: /trunk/doc/pslib/ChangeLogSDRS.tex
===================================================================
--- /trunk/doc/pslib/ChangeLogSDRS.tex	(revision 4086)
+++ /trunk/doc/pslib/ChangeLogSDRS.tex	(revision 4087)
@@ -1,3 +1,3 @@
-%%% $Id: ChangeLogSDRS.tex,v 1.122 2005-06-02 04:13:41 jhoblitt Exp $
+%%% $Id: ChangeLogSDRS.tex,v 1.123 2005-06-02 20:54:00 jhoblitt Exp $
 
 \subsection{Changes from version 00 to version 01}
@@ -666,3 +666,4 @@
 \end{itemize}
 \item add \code{PS_META_NULL}
-\end{itemize}
+\item add \code{NULL} keyword to ``Configuration files''
+\end{itemize}
Index: /trunk/doc/pslib/psLibSDRS.tex
===================================================================
--- /trunk/doc/pslib/psLibSDRS.tex	(revision 4086)
+++ /trunk/doc/pslib/psLibSDRS.tex	(revision 4087)
@@ -1,3 +1,3 @@
-%%% $Id: psLibSDRS.tex,v 1.258 2005-06-02 04:13:41 jhoblitt Exp $
+%%% $Id: psLibSDRS.tex,v 1.259 2005-06-02 20:54:00 jhoblitt Exp $
 \documentclass[panstarrs,spec]{panstarrs}
 
@@ -4319,4 +4319,16 @@
 which should not form part of the key.
 
+\paragraph{NULL values}
+
+The ``value'' of a quad may be declare to be undefined with the ``NULL''
+keyword.  ``NULL'' is allowed to co-exist with a ``comment'' and may be
+surrounded by whitespace.  Any non-whitespace character will cause of the
+``value'' to be interpreted as a string.
+
+\begin{verbatim}
+foo     STR     NULL    # string with a NULL value
+bar     STR     NULL a  # string with a value of "NULL a"
+\end{verbatim}
+
 \paragraph{Types}
 \subparagraph{Scalar \& Vector}