total size of the file. The third argument may be \code{-1} on older
FTP servers which do not return a file size in response to a retrieval
request.
+
+If the \var{url} uses the \file{http:} scheme identifier, the optional
+\var{data} argument may be given to specify a \code{POST} request
+(normally the request type is \code{GET}). The \var{data} argument
+must in standard \file{application/x-www-form-urlencoded} format;
+see the \function{urlencode()} function below.
\end{funcdesc}
\begin{funcdesc}{urlcleanup}{}
a function accepting three numeric parameters. It will be called after each
chunk of data is read from the network. \var{reporthook} is ignored for
local URLs.
+
+If the \var{url} uses the \file{http:} scheme identifier, the optional
+\var{data} argument may be given to specify a \code{POST} request
+(normally the request type is \code{GET}). The \var{data} argument
+must in standard \file{application/x-www-form-urlencoded} format;
+see the \function{urlencode()} function below.
\end{methoddesc}