diff --git a/README b/README
index 944e592..6eab0c9 100644
--- a/README
+++ b/README
@@ -1,6 +1,6 @@
 Author: Wei Yang   SLAC National Accelerator Laboratory / Stanford University
 
-rucioN2N-for-Xcache requires Xrootd release 4.8.1 and higher
+rucioN2N-for-Xcache requires xrootd. The minimum requirements of xrootd is specified in the Release Notes.
 
 This is a Xrootd (seach Github for xrootd) Ouc Name2Name plugin module to effeciently cache LHC ATLAS data files managed by the experiment's Distrubite Data Management (DDM) system (RUCIO). 
 
diff --git a/ReleaseNotes.txt b/ReleaseNotes.txt
index 2423e8b..0daa819 100644
--- a/ReleaseNotes.txt
+++ b/ReleaseNotes.txt
@@ -2,6 +2,7 @@
   * Inital version that assume /atlas/rucio is the gLFN prefix (files starting
      with /atlas/rucio follows gLFN convention), and query RUCIO to obtain a 
      list of data sources in metalink.
+  ** Require xrootd 4.8.1 and above.
 2018-09-09: v1.1
   * Tagged but didn't release
 2019-08-02: v1.2