PATCH v4 Document -background none option

[vdb at picaros.org]

Just an observation: setting the word  none  in italic hints the 
reader that this is a symbolic name or parameter.  However, it is to 
be typed in literally.  So perhaps

diff --git a/man/Xserver.man b/man/Xserver.man
index 1a36b09..023e009 100644
--- a/man/Xserver.man
+++ b/man/Xserver.man
@@ -100,6 +100,12 @@ specifies a file which contains a collection of authorization records used
 to authenticate access.  See also the \fIxdm\fP(1) and
 \fIXsecurity\fP(__miscmansuffix__) manual pages.
 .TP 8
+.B \-background none
+Asks the driver not to clear the background on startup, if supported by the
+driver.  May be useful for smooth transition with e.g. the fbdev driver.
+For security reasons this is not the default as the screen contents might
+show a previous user session.
+.TP 8
 .B \-br
 sets the default root window to solid black instead of the standard root weave
 pattern.   This is the default unless -retro or -wr is specified.