diff --git a/Magento2/Sniffs/Legacy/PhtmlTemplateSniff.php b/Magento2/Sniffs/Legacy/PhtmlTemplateSniff.php
new file mode 100644
index 00000000..67d74575
--- /dev/null
+++ b/Magento2/Sniffs/Legacy/PhtmlTemplateSniff.php
@@ -0,0 +1,148 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+declare(strict_types = 1);
+
+namespace Magento2\Sniffs\Legacy;
+
+use PHP_CodeSniffer\Files\File;
+use PHP_CodeSniffer\Sniffs\Sniff;
+
+class PhtmlTemplateSniff implements Sniff
+{
+    private const WARNING_CODE = 'PhtmlTemplateObsolete';
+
+    private const OBSOLETE_REGEX_IN_SPECIFIC_PHTML_TEMPLATES = [
+        '/(["\'])jquery\/ui\1/' => 'Please do not use "jquery/ui" library in templates. Use needed jquery ' .
+            'ui widget instead.',
+        '/data-mage-init=(?:\'|")(?!\s*{\s*"[^"]+")/' => 'Please do not initialize JS component in php. Do ' .
+            'it in template.',
+        '@x-magento-init.>(?!\s*+{\s*"[^"]+"\s*:\s*{\s*"[\w/-]+")@i' => 'Please do not initialize JS component ' .
+            'in php. Do it in template.',
+    ];
+    
+    /**
+     * @inheritdoc
+     */
+    public function register(): array
+    {
+        return [
+            T_OBJECT_OPERATOR,
+            T_INLINE_HTML,
+            T_HEREDOC
+        ];
+    }
+
+    /**
+     * @inheritdoc
+     */
+    public function process(File $phpcsFile, $stackPtr)
+    {
+        $tokens = $phpcsFile->getTokens();
+        if ($tokens[$stackPtr]['code'] === T_OBJECT_OPERATOR) {
+            $this->checkBlockVariable($phpcsFile, $stackPtr, $tokens);
+            $this->checkThisVariable($phpcsFile, $stackPtr, $tokens);
+        }
+        if ($tokens[$stackPtr]['code'] === T_INLINE_HTML || $tokens[$stackPtr]['code'] === T_HEREDOC) {
+            $this->checkHtml($phpcsFile, $stackPtr);
+            
+            $file = $phpcsFile->getFilename();
+
+            if (strpos($file, '/view/frontend/templates/') !== false
+                || strpos($file, '/view/base/templates/') !== false
+            ) {
+                $this->checkHtmlSpecificFiles($phpcsFile, $stackPtr);
+            }
+        }
+    }
+    
+    /**
+     * Check access to protected and private members of Block
+     *
+     * @param File $phpcsFile
+     * @param int $stackPtr
+     * @param array $tokens
+     */
+    private function checkBlockVariable(File $phpcsFile, int $stackPtr, array $tokens): void
+    {
+        $varPos = $phpcsFile->findPrevious(T_VARIABLE, $stackPtr - 1);
+        if ($tokens[$varPos]['content'] !== '$block') {
+            return;
+        }
+        $stringPos = $phpcsFile->findNext(T_STRING, $stackPtr + 1);
+        if (strpos($tokens[$stringPos]['content'], '_') === 0) {
+            $phpcsFile->addWarning(
+                'Access to protected and private members of Block class is ' .
+                'obsolete in phtml templates. Use only public members.',
+                $stringPos,
+                self::WARNING_CODE
+            );
+        }
+    }
+
+    /**
+     * Check access to members and methods of Block class through $this
+     *
+     * @param File $phpcsFile
+     * @param int $stackPtr
+     * @param array $tokens
+     */
+    private function checkThisVariable(File $phpcsFile, int $stackPtr, array $tokens): void
+    {
+        $varPos = $phpcsFile->findPrevious(T_VARIABLE, $stackPtr - 1);
+        if ($tokens[$varPos]['content'] !== '$this') {
+            return;
+        }
+        $stringPos = $phpcsFile->findNext(T_STRING, $stackPtr + 1);
+        if (strpos($tokens[$stringPos]['content'], 'helper') === false) {
+            $phpcsFile->addWarning(
+                'Access to members and methods of Block class through $this is ' .
+                'obsolete in phtml templates. Use only $block instead of $this.',
+                $stringPos,
+                self::WARNING_CODE
+            );
+        }
+    }
+
+    /**
+     * Check use of "text/javascript" type
+     *
+     * @param File $phpcsFile
+     * @param int $stackPtr
+     */
+    private function checkHtml(File $phpcsFile, int $stackPtr): void
+    {
+        $content = $phpcsFile->getTokensAsString($stackPtr, 1);
+        
+        if (preg_match('/type="text\/javascript"/', $content)) {
+            $phpcsFile->addWarning(
+                'Please do not use "text/javascript" type attribute.',
+                $stackPtr,
+                self::WARNING_CODE
+            );
+        }
+    }
+
+    /**
+     * Check of some obsoletes uses in specific files
+     *
+     * @param File $phpcsFile
+     * @param int $stackPtr
+     */
+    private function checkHtmlSpecificFiles(File $phpcsFile, int $stackPtr): void
+    {
+        $content = $phpcsFile->getTokensAsString($stackPtr, 1);
+        
+        foreach (self::OBSOLETE_REGEX_IN_SPECIFIC_PHTML_TEMPLATES as $obsoleteRegex => $errorMessage) {
+            if (preg_match($obsoleteRegex, $content)) {
+                $phpcsFile->addWarning(
+                    $errorMessage,
+                    $stackPtr,
+                    self::WARNING_CODE
+                );
+            }
+        }
+    }
+}
diff --git a/Magento2/Tests/Legacy/PhtmlTemplateUnitTest.php b/Magento2/Tests/Legacy/PhtmlTemplateUnitTest.php
new file mode 100644
index 00000000..46417690
--- /dev/null
+++ b/Magento2/Tests/Legacy/PhtmlTemplateUnitTest.php
@@ -0,0 +1,82 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+namespace Magento2\Tests\Legacy;
+
+use DirectoryIterator;
+use PHP_CodeSniffer\Tests\Standards\AbstractSniffUnitTest;
+use RecursiveDirectoryIterator;
+use RecursiveIteratorIterator;
+
+class PhtmlTemplateUnitTest extends AbstractSniffUnitTest
+{
+    /**
+     * @inheritdoc
+     */
+    protected function getTestFiles($testFileBase): array
+    {
+        $testFiles = [];
+
+        $dir = __DIR__.'/_files/PhtmlTemplateUnitTest';
+        $di  = new RecursiveIteratorIterator(new RecursiveDirectoryIterator($dir));
+
+        /**
+         * @var DirectoryIterator $file
+         */
+        foreach ($di as $file) {
+            if ($file->isDir()) {
+                continue;
+            }
+            $path = $file->getPathname();
+            if ($path !== $testFileBase.'php' && substr($path, -5) !== 'fixed' && substr($path, -4) !== '.bak') {
+                $testFiles[] = $path;
+            }
+        }
+
+        // Put them in order.
+        sort($testFiles);
+        
+        return $testFiles;
+    }
+
+    /**
+     * @inheritdoc
+     */
+    public function getErrorList()
+    {
+        return [];
+    }
+
+    /**
+     * @inheritdoc
+     */
+    public function getWarningList($testFile = '')
+    {
+        if ($testFile === 'PhtmlTemplateUnitTest.1.phtml' || $testFile === 'PhtmlTemplateUnitTest.2.phtml') {
+            return [
+                7 => 1,
+                9 => 1,
+                13 => 1,
+                20 => 1,
+                22 => 1,
+                23 => 1,
+                27 => 1,
+                33 => 1,
+                39 => 1
+            ];
+        }
+        if ($testFile === 'PhtmlTemplateUnitTest.3.phtml')
+        {
+            return [
+                9 => 1,
+                20 => 1,
+                22 => 1,
+                23 => 1,
+                27 => 1,
+            ];
+        }
+        return [];
+    }
+}
diff --git a/Magento2/Tests/Legacy/_files/PhtmlTemplateUnitTest/view/adminhtml/templates/PhtmlTemplateUnitTest.3.phtml b/Magento2/Tests/Legacy/_files/PhtmlTemplateUnitTest/view/adminhtml/templates/PhtmlTemplateUnitTest.3.phtml
new file mode 100644
index 00000000..772783c9
--- /dev/null
+++ b/Magento2/Tests/Legacy/_files/PhtmlTemplateUnitTest/view/adminhtml/templates/PhtmlTemplateUnitTest.3.phtml
@@ -0,0 +1,40 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+?>
+<script type="text/x-magento-init">
+</script>
+<script type="text/javascript">
+</script>
+<div id="block-testing"
+     class="block shipping"
+     data-mage-init='{}'
+>
+<?php
+function _testing()
+{
+    return true;
+}
+$_productCollection = $block->_getTestFunction();
+$block->getTestFunction();
+$_something = $this->something();
+$block->_getTest();
+$block = _testing();
+?>
+<?php
+$block->_getTestAnotherFunction();
+?>
+
+<?php $scriptString = <<<script
+    require([
+        "jquery",
+        "jquery/ui",
+    ], function ($, Confirm) {
+    });
+script;
+$this->helper();
+?>
+<script type="jquery/ui">
+</script>
diff --git a/Magento2/Tests/Legacy/_files/PhtmlTemplateUnitTest/view/base/templates/PhtmlTemplateUnitTest.1.phtml b/Magento2/Tests/Legacy/_files/PhtmlTemplateUnitTest/view/base/templates/PhtmlTemplateUnitTest.1.phtml
new file mode 100644
index 00000000..772783c9
--- /dev/null
+++ b/Magento2/Tests/Legacy/_files/PhtmlTemplateUnitTest/view/base/templates/PhtmlTemplateUnitTest.1.phtml
@@ -0,0 +1,40 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+?>
+<script type="text/x-magento-init">
+</script>
+<script type="text/javascript">
+</script>
+<div id="block-testing"
+     class="block shipping"
+     data-mage-init='{}'
+>
+<?php
+function _testing()
+{
+    return true;
+}
+$_productCollection = $block->_getTestFunction();
+$block->getTestFunction();
+$_something = $this->something();
+$block->_getTest();
+$block = _testing();
+?>
+<?php
+$block->_getTestAnotherFunction();
+?>
+
+<?php $scriptString = <<<script
+    require([
+        "jquery",
+        "jquery/ui",
+    ], function ($, Confirm) {
+    });
+script;
+$this->helper();
+?>
+<script type="jquery/ui">
+</script>
diff --git a/Magento2/Tests/Legacy/_files/PhtmlTemplateUnitTest/view/frontend/templates/PhtmlTemplateUnitTest.2.phtml b/Magento2/Tests/Legacy/_files/PhtmlTemplateUnitTest/view/frontend/templates/PhtmlTemplateUnitTest.2.phtml
new file mode 100644
index 00000000..772783c9
--- /dev/null
+++ b/Magento2/Tests/Legacy/_files/PhtmlTemplateUnitTest/view/frontend/templates/PhtmlTemplateUnitTest.2.phtml
@@ -0,0 +1,40 @@
+<?php
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+ */
+?>
+<script type="text/x-magento-init">
+</script>
+<script type="text/javascript">
+</script>
+<div id="block-testing"
+     class="block shipping"
+     data-mage-init='{}'
+>
+<?php
+function _testing()
+{
+    return true;
+}
+$_productCollection = $block->_getTestFunction();
+$block->getTestFunction();
+$_something = $this->something();
+$block->_getTest();
+$block = _testing();
+?>
+<?php
+$block->_getTestAnotherFunction();
+?>
+
+<?php $scriptString = <<<script
+    require([
+        "jquery",
+        "jquery/ui",
+    ], function ($, Confirm) {
+    });
+script;
+$this->helper();
+?>
+<script type="jquery/ui">
+</script>
diff --git a/Magento2/ruleset.xml b/Magento2/ruleset.xml
index d902a793..1b1c7f1b 100644
--- a/Magento2/ruleset.xml
+++ b/Magento2/ruleset.xml
@@ -308,6 +308,11 @@
         <severity>8</severity>
         <type>warning</type>
     </rule>
+    <rule ref="Magento2.Legacy.PhtmlTemplate">
+        <include-pattern>*\.phtml$</include-pattern>
+        <severity>8</severity>
+        <type>warning</type>
+    </rule>
 
     <!-- Severity 7 warnings: General code issues. -->
     <rule ref="Generic.Arrays.DisallowLongArraySyntax">