diff --git a/CakePHP/Sniffs/NamingConventions/ValidFunctionNameSniff.php b/CakePHP/Sniffs/NamingConventions/ValidFunctionNameSniff.php
index 65037bf..a3ed2f6 100644
--- a/CakePHP/Sniffs/NamingConventions/ValidFunctionNameSniff.php
+++ b/CakePHP/Sniffs/NamingConventions/ValidFunctionNameSniff.php
@@ -27,9 +27,9 @@ class ValidFunctionNameSniff extends AbstractScopeSniff
     /**
      * A list of all PHP magic methods.
      *
-     * @var array
+     * @var array<string>
      */
-    protected array $_magicMethods = [
+    protected array $magicMethods = [
         'construct',
         'destruct',
         'call',
@@ -54,7 +54,7 @@ class ValidFunctionNameSniff extends AbstractScopeSniff
      */
     public function __construct()
     {
-        parent::__construct([T_CLASS, T_INTERFACE, T_TRAIT], [T_FUNCTION], true);
+        parent::__construct([T_CLASS, T_INTERFACE, T_TRAIT, T_ENUM], [T_FUNCTION], true);
     }
 
     /**
@@ -71,7 +71,7 @@ protected function processTokenWithinScope(File $phpcsFile, $stackPtr, $currScop
         $errorData = [$className . '::' . $methodName];
 
         // Ignore magic methods
-        if (preg_match('/^__(' . implode('|', $this->_magicMethods) . ')$/', $methodName)) {
+        if (preg_match('/^__(' . implode('|', $this->magicMethods) . ')$/', $methodName)) {
             return;
         }
 
@@ -89,6 +89,17 @@ protected function processTokenWithinScope(File $phpcsFile, $stackPtr, $currScop
 
             return;
         }
+
+        // Check non-public methods for underscore prefix
+        if ($isPublic === false && $methodName[0] === '_') {
+            // Allow CakePHP Entity accessor/mutator pattern: _getField(), _setField()
+            if (preg_match('/^_(get|set)[A-Z]/', $methodName)) {
+                return;
+            }
+
+            $error = 'Non-public method name "%s" should not be prefixed with underscore';
+            $phpcsFile->addError($error, $stackPtr, 'ProtectedWithUnderscore', $errorData);
+        }
     }
 
     /**
diff --git a/CakePHP/Tests/NamingConventions/ValidFunctionNameUnitTest.inc b/CakePHP/Tests/NamingConventions/ValidFunctionNameUnitTest.inc
index e4bc565..837502c 100644
--- a/CakePHP/Tests/NamingConventions/ValidFunctionNameUnitTest.inc
+++ b/CakePHP/Tests/NamingConventions/ValidFunctionNameUnitTest.inc
@@ -29,7 +29,7 @@ class FunctionNames
 
     protected function _someFunc()
     {
-        // code here
+        // code here - error: underscore prefix not allowed
     }
 
     protected function noUnderscorePrefix()
@@ -40,6 +40,22 @@ class FunctionNames
         };
     }
 
+    // Entity accessor/mutator patterns - should be allowed
+    protected function _getName()
+    {
+        return $this->name;
+    }
+
+    protected function _setName($name)
+    {
+        $this->name = $name;
+    }
+
+    protected function _getFullName()
+    {
+        return $this->first_name . ' ' . $this->last_name;
+    }
+
     public function __call($name, $arguments)
     {
     }
diff --git a/CakePHP/Tests/NamingConventions/ValidFunctionNameUnitTest.php b/CakePHP/Tests/NamingConventions/ValidFunctionNameUnitTest.php
index 2816783..9ac89c5 100644
--- a/CakePHP/Tests/NamingConventions/ValidFunctionNameUnitTest.php
+++ b/CakePHP/Tests/NamingConventions/ValidFunctionNameUnitTest.php
@@ -9,19 +9,21 @@ class ValidFunctionNameUnitTest extends AbstractSniffTestCase
     /**
      * @inheritDoc
      */
-    public function getErrorList()
+    public function getErrorList(): array
     {
         return [
             6 => 1,
-            87 => 1,
-            96 => 1,
+            30 => 1,
+            103 => 1,
+            112 => 1,
+            136 => 1,
         ];
     }
 
     /**
      * @inheritDoc
      */
-    public function getWarningList()
+    public function getWarningList(): array
     {
         return [];
     }
diff --git a/CakePHP/ruleset.xml b/CakePHP/ruleset.xml
index f41ec35..13225b5 100644
--- a/CakePHP/ruleset.xml
+++ b/CakePHP/ruleset.xml
@@ -18,10 +18,9 @@
         <exclude name="PSR12.Files.FileHeader.SpacingAfterUseBlock"/>
         <exclude name="PSR12.Files.FileHeader.SpacingAfterUseFunctionBlock"/>
         <!--
-        Property and method names with underscore prefix are allowed in CakePHP.
-        Not using underscore prefix is a recommendation of PSR2, not a requirement.
+        We use our own CakePHP.NamingConventions.ValidFunctionName sniff which allows
+        Entity accessor/mutator pattern (_getField, _setField) while enforcing PSR naming elsewhere.
         -->
-        <exclude name="PSR2.Classes.PropertyDeclaration.Underscore"/>
         <exclude name="PSR2.Methods.MethodDeclaration.Underscore"/>
     </rule>
 
@@ -256,6 +255,10 @@
     <rule ref="SlevomatCodingStandard.Attributes.RequireAttributeAfterDocComment"/>
     <rule ref="SlevomatCodingStandard.Classes.BackedEnumTypeSpacing"/>
     <rule ref="SlevomatCodingStandard.ControlStructures.RequireShortTernaryOperator"/>
+    <rule ref="SlevomatCodingStandard.ControlStructures.RequireNullCoalesceEqualOperator"/>
+    <rule ref="SlevomatCodingStandard.ControlStructures.RequireNullSafeObjectOperator"/>
+    <rule ref="SlevomatCodingStandard.Classes.RequireSelfReference"/>
+    <rule ref="SlevomatCodingStandard.TypeHints.NullTypeHintOnLastPosition"/>
 
     <!-- phpcs Zend sniffs -->
     <rule ref="Zend.NamingConventions.ValidVariableName">