diff --git a/README.md b/README.md
index b06bab2a..c49cba7b 100644
--- a/README.md
+++ b/README.md
@@ -53,7 +53,6 @@ potentially very difficult to debug due to dissimilar or unsupported package ver
         - [Step 2: Run PHP-Scoper](#step-2-run-php-scoper)
 - [Recommendations](#recommendations)
 - [Further Reading](docs/further-reading.md#further-reading)
-    - [Polyfills](docs/further-reading.md#polyfills)
     - [How to deal with unknown third-party symbols](docs/further-reading.md#how-to-deal-with-unknown-third-party-symbols)
     - [Autoload aliases](docs/further-reading.md#autoload-aliases)
         - [Class aliases](docs/further-reading.md#class-aliases)
diff --git a/docs/configuration.md b/docs/configuration.md
index 4c75560a..3e181bff 100644
--- a/docs/configuration.md
+++ b/docs/configuration.md
@@ -207,9 +207,44 @@ return [
 
 This enriches the list of Symbols PHP-Scoper's Reflector considers as "internal",
 i.e. PHP engine or extension symbols. Such symbols will be left completely 
-untouched.
+untouched.*
 
-This feature should be use very carefully as it can easily break the Composer
+*: There is _one_ exception, which is declarations of functions. If you have the function
+`trigger_deprecation` excluded, then any usage of it in the code will be left alone:
+
+```php
+use function trigger_deprecation; // Will not be turned into Prefix\trigger_deprecation
+```
+
+However, PHP-Scoper may come across its declaration:
+
+```php
+// global namespace!
+
+if (!function_exists('trigger_deprecation')) {
+    function trigger_deprecation() {}
+}
+```
+
+Then it will be scoped into:
+
+```php
+namespace Prefix;
+
+if (!function_exists('Prefix\trigger_deprecation')) {
+    function trigger_deprecation() {}
+}
+```
+
+Indeed, the namespace _needs_ to be added in order to not break autoloading, in which
+case wrapping the function declaration into a non-namespace could work, but is tricky
+(so not implemented so far, PoC for supporting it are welcomed) hence was not attempted.
+
+So if left alone, this will break any piece of code that relied on `\trigger_deprecation`,
+which is why PHP-Scoper will still add an alias for it, as if it was an exposed function.
+Another benefit of this, is that it allows to scope any polyfill without any issues.
+
+**WARNING**: This exclusion feature should be use very carefully as it can easily break the Composer
 auto-loading. Indeed, if you have the following package:
 
 ```json
diff --git a/docs/further-reading.md b/docs/further-reading.md
index e7e90c31..33ab9a6b 100644
--- a/docs/further-reading.md
+++ b/docs/further-reading.md
@@ -1,69 +1,11 @@
 ## Further Reading
 
-- [Polyfills](#polyfills)
 - [How to deal with unknown third-party symbols](#how-to-deal-with-unknown-third-party-symbols)
 - [Autoload aliases](#autoload-aliases)
   - [Class aliases](#class-aliases)
   - [Function aliases](#function-aliases)
 
 
-### Polyfills
-
-**Note: should be obsolete as of 0.18.0.**
-
-At the moment there is no way to automatically handles polyfills. This is mainly
-due to the nature of polyfills: the code is sometimes a bit... special and there
-is also not only one way on how to approach it.
-
-If all of what you have is Symfony polyfills however, the following should get
-you covered:
-
-```php
-<?php declare(strict_types=1);  // scoper.inc.php
-
-use Isolated\Symfony\Component\Finder\Finder;
-
-$polyfillsBootstraps = array_map(
-    static fn (SplFileInfo $fileInfo) => $fileInfo->getPathname(),
-    iterator_to_array(
-        Finder::create()
-            ->files()
-            ->in(__DIR__ . '/vendor/symfony/polyfill-*')
-            ->name('bootstrap*.php'),
-        false,
-    ),
-);
-
-$polyfillsStubs = array_map(
-    static fn (SplFileInfo $fileInfo) => $fileInfo->getPathname(),
-    iterator_to_array(
-        Finder::create()
-            ->files()
-            ->in(__DIR__ . '/vendor/symfony/polyfill-*/Resources/stubs')
-            ->name('*.php'),
-        false,
-    ),
-);
-
-return [
-    // ...
-    
-    'exclude-namespaces' => [
-        'Symfony\Polyfill'
-    ],
-    'exclude-constants' => [
-        // Symfony global constants
-        '/^SYMFONY\_[\p{L}_]+$/',
-    ],
-    'exclude-files' => [
-        ...$polyfillsBootstraps,
-        ...$polyfillsStubs,
-    ],
-];
-
-```
-
-
 ### How to deal with unknown third-party symbols
 
 If you consider the following code: