update README to match the filters
diff --git a/README.md b/README.md
index 5c54057..3a624ea 100644
--- a/README.md
+++ b/README.md
@@ -284,17 +284,21 @@
ROFs.AddFilter(afero.NewReadonlyFilter())
```
The ROFs behaves like a normal afero.Fs now, with the only exception, that it
-provides a readonly view of the underlying Fs.
+provides a readonly view of the underlying AppFs.
-The FilterFs is run before the source Fs, any non nil error is returned
-to the caller without going to the source Fs. If every filter in the
-chain returns a nil error, the call is sent to the source Fs.
+The FilterFs is run before the source Fs and may intercept the call to the
+underlying source Fs and can modify the returned data. If it does not wish to
+do so, it just returns the data from the source.
-The `AddFilter` adds a new filter before any existing filters.
+The `AddFilter` adds a new FilterFs before any existing filters.
## Available filters
* NewReadonlyFilter() - provide a read only view of the source Fs
+* NewRegexpFilter(*regexp.Regexp) - provide a filtered view on file names, any
+file (not directory) NOT matching the passed regexp will be treated as
+non-existing
+
# About the project
