nxagent manpage: Extend keyboard documentation

nx-X11/programs/Xserver/hw/nxagent/man/nxagent.1

@@ -500,8 +500,29 @@ set resizing support (default: true)
 .B fullscreen=<bool>
 start or resume a session in fullscreen mode (default: off)
 .TP 8
-.B keyboard=<string>
-set remote keyboard layout
+.B keyboard=<string> or kbtype=<string>
+
+.BR query | <model>/<layout>
+
+.RS 8
+.TP 8
+.I query
+use the default XKB keyboard layout (see below) and only allow clients
+to query the settings but prevent any changes. \fIquery\fR is
+especially helpful for setups where you need to set/modify the actual
+keyboard layout using core X protocol functions (e.g. via \fBxmodmap\fR). It is used for
+MacOS X clients to handle some keyboard problems that are special for
+this platform.  Note that in this case XKEYBOARD will always report
+the default layout which will most likely not match the experienced
+settings.
+.TP 8
+.I <model>/<layout>
+use the given model and layout. You can not modify keyboard rules,
+variants or options.
+.TP 8
+If \fIkeyboard\fR is omitted the internal defaults of \fBnxagent\fR
+will used (rules: xfree86, layout: us, model: pc102).
+.RE
 .TP 8
 .B keyconv=<string>
 set keycode conversion mode
@@ -542,9 +563,6 @@ enable using shared memory
 .B shpix=<bool>
 enable shared pixmaps support
 .TP 8
-.B kbtype=<string>
-set remote keyboard type
-.TP 8
 .B client=<string>
 type of connecting operating system (supported: \fIlinux\fR,
 \fIwindows\fR, \fIsolaris\fR and \fImacosx\fR)