diff --git a/crpptbx/iround_os.m b/crpptbx/iround_os.m
index 92905ffbc13fa1a152cae28e32502081414f1725..c968068077c68720799850dfae7ba911f7c14aa3 100644
--- a/crpptbx/iround_os.m
+++ b/crpptbx/iround_os.m
@@ -1,12 +1,13 @@
 function  [is,sigi]=iround_os(sig,val)
+%
 % Given two arrays sig and val, for each element in val 
 % returns the index and value of the nearest element in sig.
 % 
-% sig and/or val can be non-monotonic
+% sig and/or val can be non-monotonic (contrary to TCV iround which requires sig to be monotonic)
 %
 % Example:
 %
-% >> [i,sigi]=iround_OS(sig,val);
+% >> [i,sigi]=iround_os(sig,val);
 %
 %
 %