diff --git a/readme.md b/readme.md
index e0cb5a9..ce6dc8f 100644
--- a/readme.md
+++ b/readme.md
@@ -223,24 +223,29 @@ fn(mixed $carry, mixed $value, mixed $key): mixed
 
 ### Filtering: `filter`
 
+Create a generator that yields only the items of the input collection that the predicate returns _truthy_ for.
+
 ```php
 use Dakujem\Toru\Itera;
 
 Itera::filter(iterable $input, callable $predicate): iterable
 ```
 
-Filter elements out based on a callable predicate.  
-When the predicate returns _falsey_, the element is rejected.
+Accept and eliminate elements based on a callable predicate.  
+When the predicate returns _truthy_, the element is accepted and yielded.  
+When the predicate returns _falsey_, the element is rejected and skipped.
 
 The predicate signature is
 ```php
 fn(mixed $value, mixed $key): bool
 ```
 
+Similar to `array_filter`, `iter\filter`.
+
 >
 > Sidenote
 > 
-> Native CallbackFilterIterator may be used for similar results
+> Native `CallbackFilterIterator` may be used for similar results:
 > ```php
 > new CallbackFilterIterator(Itera::toIterator($input), $predicate)
 > ```