diff --git a/README b/README
index 5690bc32..5d0bb3ee 100644
--- a/README
+++ b/README
@@ -473,6 +473,10 @@ guidelines in mind:
   the same thing and require an argument, offer only --something as a
   completion when completing option names starting with a dash, but do
   implement required argument processing for all -s, -S, and --something.
+  Note that GNU versions of various standard commands tend to have long
+  options while other userland implementations of the same commands may
+  not have them, and it would be good to have the completions work for
+  as many userlands as possible so things aren't always that simple.
 
 - Do not write to the file-system under any circumstances. This can
   create race conditions, is inefficient, violates the principle of