diff --git a/.phpstan/constants.php b/.phpstan/constants.php
index a5eeecfa..1f5f9bb3 100644
--- a/.phpstan/constants.php
+++ b/.phpstan/constants.php
@@ -3,3 +3,6 @@
 define('NAILS_COMMON_PATH', './');
 define('NAILS_CI_SYSTEM_PATH', NAILS_COMMON_PATH . 'vendor/pocketarc/codeigniter/system/');
 define('BASEPATH', NAILS_CI_SYSTEM_PATH);
+define('NAILS_DB_PREFIX', 'nails_');
+
+require_once dirname(__DIR__) . '/src/FindReplace/Interfaces/Exclusion.php';
diff --git a/src/Common/FindReplace/Exclusion/Package.php b/src/Common/FindReplace/Exclusion/Package.php
new file mode 100644
index 00000000..bad867c9
--- /dev/null
+++ b/src/Common/FindReplace/Exclusion/Package.php
@@ -0,0 +1,20 @@
+<?php
+
+namespace Nails\Common\FindReplace\Exclusion;
+
+use Nails\FindReplace\Interfaces\Exclusion;
+
+class Package implements Exclusion
+{
+    public function hidden(): array
+    {
+        return [
+            NAILS_DB_PREFIX . 'app_setting',
+        ];
+    }
+
+    public function readOnly(): array
+    {
+        return [];
+    }
+}
diff --git a/src/FindReplace/Interfaces/Exclusion.php b/src/FindReplace/Interfaces/Exclusion.php
new file mode 100644
index 00000000..d261e47e
--- /dev/null
+++ b/src/FindReplace/Interfaces/Exclusion.php
@@ -0,0 +1,24 @@
+<?php
+
+namespace Nails\FindReplace\Interfaces;
+
+if (interface_exists(Exclusion::class, false)) {
+    return;
+}
+
+interface Exclusion
+{
+    /**
+     * Never searched. Entries are `table`, `table.*`, `table.column`, or a delimited PCRE pattern.
+     *
+     * @return list<string>
+     */
+    public function hidden(): array;
+
+    /**
+     * Searched and shown, never replaced. Same entry format as hidden().
+     *
+     * @return list<string>
+     */
+    public function readOnly(): array;
+}
diff --git a/tests/FindReplace/Exclusion/PackageTest.php b/tests/FindReplace/Exclusion/PackageTest.php
new file mode 100644
index 00000000..7cd45e15
--- /dev/null
+++ b/tests/FindReplace/Exclusion/PackageTest.php
@@ -0,0 +1,34 @@
+<?php
+
+namespace Tests\FindReplace\Exclusion;
+
+use Nails\Common\FindReplace\Exclusion\Package;
+use PHPUnit\Framework\TestCase;
+
+class PackageTest extends TestCase
+{
+    public static function setUpBeforeClass(): void
+    {
+        if (!defined('NAILS_DB_PREFIX')) {
+            define('NAILS_DB_PREFIX', 'nails_');
+        }
+    }
+
+    public function testHidden(): void
+    {
+        self::assertSame(
+            [
+                NAILS_DB_PREFIX . 'app_setting',
+            ],
+            (new Package())->hidden()
+        );
+    }
+
+    public function testReadOnly(): void
+    {
+        self::assertSame(
+            [],
+            (new Package())->readOnly()
+        );
+    }
+}
diff --git a/tests/bootstrap.php b/tests/bootstrap.php
index 12a66d50..4c88e682 100644
--- a/tests/bootstrap.php
+++ b/tests/bootstrap.php
@@ -63,3 +63,5 @@
 
     Testing::bootstrapModule(__FILE__);
 }
+
+require_once dirname(__DIR__) . '/src/FindReplace/Interfaces/Exclusion.php';