diff --git a/README.txt b/README.txt
index 589d0d3..dd7fe4f 100644
--- a/README.txt
+++ b/README.txt
@@ -1,3 +1,9 @@
+Summary:
+
+This is an old plug-in to Solr 3.x to add spatial filtering on multi-valued fields, and distance-sorting on
+these multi-valued fields as well.  In Solr 4.x and beyond, you use the so-called "RPT" field type to get
+the same capabilities.
+
 Author: David Smiley
 
 You may find supplemental instructions online:
@@ -50,4 +56,4 @@ CHANGES
         * add cache enabling recommendation into README.txt (cache name is confusing a little)
         * fix for UnsupportedOpEx on debugQuery=on for geodist func (but my toString() impl seems overcomplicated)
 
- 1.0.2: (first public release)
\ No newline at end of file
+ 1.0.2: (first public release)