diff --git a/README b/README
index 3c9f078e4f87e7d6eca1c2f708096fed75bc371b..413c967a6042e3f2a22690cd198b95838723272d 100644
--- a/README
+++ b/README
@@ -41,3 +41,8 @@ NOTE: the current version of iobber does not recognise chunks' syntactic heads.
 Also, it is unable to recognise discontinuous chunks. Both types of information
 may be included in ccl format and this is likely to be supported in the future.
 
+
+If the input file contains annotations in channels other than those defined
+in the config, they will be preserved (this makes it possible to e.g. chunk
+files already annotated with named entities).
+