Document ERR and OK
diff --git a/Doc/lib/libcurses.tex b/Doc/lib/libcurses.tex
index 802a9f9..00dec6d 100644
--- a/Doc/lib/libcurses.tex
+++ b/Doc/lib/libcurses.tex
@@ -1026,6 +1026,17 @@
The \module{curses} module defines the following data members:
+\begin{datadesc}{ERR}
+Some curses routines that return an integer, such as
+\function{getch()}, return ERR upon failure.
+\end{datadesc}
+
+\begin{datadesc}{OK}
+Some curses routines that return an integer, such as
+\function{napms()}, return OK upon success.
+
+\end{datadesc}
+
\begin{datadesc}{version}
A string representing the current version of the module.
Also available as \constant{__version__}.