Explain using a before-string to put something in the margin.

diff --git a/lispref/display.texi b/lispref/display.texi
index 13cea17b514721ac9020449cbf043ce33d1c0138..afdbc347d6166a7aad95d4856f528a15cb4cd9bc 100644 (file)
--- a/lispref/display.texi
+++ b/lispref/display.texi
@@ -2356,6 +2356,14 @@ display specification of the form @code{(margin right-margin)} or
 use that display specification along with the display specification for
 the image.
 
+  If you put such a display specification directly on text in the
+buffer, the specified margin display appears @emph{instead of} that
+buffer text itself.  To put something in the margin @emph{in
+association with} certain buffer text without preventing or altering
+the display of that text, put a @code{before-string} property on the
+text and put the display specification on the contents of the
+before-string.
+
   Before the display margins can display anything, you must give
 them a nonzero width.  The usual way to do that is to set these
 variables: