diff --git a/application/Espo/Core/Field/Address/AddressBuilder.php b/application/Espo/Core/Field/Address/AddressBuilder.php
index 02880763e2..d9f1f8d0a9 100644
--- a/application/Espo/Core/Field/Address/AddressBuilder.php
+++ b/application/Espo/Core/Field/Address/AddressBuilder.php
@@ -36,15 +36,15 @@ use Espo\Core\Field\Address;
  */
 class AddressBuilder
 {
-    protected $street;
+    private ?string $street;
 
-    protected $city;
+    private ?string$city;
 
-    protected $country;
+    private ?string $country;
 
-    protected $state;
+    private ?string $state;
 
-    protected $postalCode;
+    private ?string $postalCode;
 
     public function clone(Address $address): self
     {
diff --git a/application/Espo/Core/Field/Address/AddressFormatterFactory.php b/application/Espo/Core/Field/Address/AddressFormatterFactory.php
index 862e772293..6cbf190843 100644
--- a/application/Espo/Core/Field/Address/AddressFormatterFactory.php
+++ b/application/Espo/Core/Field/Address/AddressFormatterFactory.php
@@ -38,11 +38,11 @@ use Espo\Core\{
 
 class AddressFormatterFactory
 {
-    private $metadataProvider;
+    private AddressFormatterMetadataProvider $metadataProvider;
 
-    private $injectableFactory;
+    private InjectableFactory $injectableFactory;
 
-    private $config;
+    private Config $config;
 
     public function __construct(
         AddressFormatterMetadataProvider $metadataProvider,
@@ -56,6 +56,7 @@ class AddressFormatterFactory
 
     public function create(int $format): AddressFormatter
     {
+        /** @var ?class-string */
         $className = $this->metadataProvider->getFormatterClassName($format);
 
         if (!$className) {
diff --git a/application/Espo/Core/Field/Currency/CurrencyConfigDataProvider.php b/application/Espo/Core/Field/Currency/CurrencyConfigDataProvider.php
index bc78f55004..72849eebde 100644
--- a/application/Espo/Core/Field/Currency/CurrencyConfigDataProvider.php
+++ b/application/Espo/Core/Field/Currency/CurrencyConfigDataProvider.php
@@ -35,7 +35,7 @@ use RuntimeException;
 
 class CurrencyConfigDataProvider
 {
-    protected $config;
+    private Config $config;
 
     public function __construct(Config $config)
     {
@@ -61,7 +61,7 @@ class CurrencyConfigDataProvider
     /**
      * Get a list of available currencies.
      *
-     * @return array<int, string>
+     * @return array<int,string>
      */
     public function getCurrencyList(): array
     {
diff --git a/application/Espo/Core/Field/Currency/CurrencyConverter.php b/application/Espo/Core/Field/Currency/CurrencyConverter.php
index f3ad7369e2..36afaf0ea2 100644
--- a/application/Espo/Core/Field/Currency/CurrencyConverter.php
+++ b/application/Espo/Core/Field/Currency/CurrencyConverter.php
@@ -38,7 +38,7 @@ use RuntimeException;
  */
 class CurrencyConverter
 {
-    protected $configDataProvider;
+    private CurrencyConfigDataProvider $configDataProvider;
 
     public function __construct(CurrencyConfigDataProvider $configDataProvider)
     {
diff --git a/application/Espo/Core/Field/Currency/CurrencyRates.php b/application/Espo/Core/Field/Currency/CurrencyRates.php
index 92a4daef9a..c460ea7a69 100644
--- a/application/Espo/Core/Field/Currency/CurrencyRates.php
+++ b/application/Espo/Core/Field/Currency/CurrencyRates.php
@@ -36,7 +36,10 @@ use RuntimeException;
  */
 class CurrencyRates
 {
-    private $data = [];
+    /**
+     * @var array<string,float>
+     */
+    private array $data = [];
 
     private function __construct()
     {
@@ -56,6 +59,9 @@ class CurrencyRates
         return $this->data[$currencyCode];
     }
 
+    /**
+     * @param array<string,float> $data
+     */
     public static function fromArray(array $data): self
     {
         $obj = new self();
diff --git a/application/Espo/Core/Field/Date.php b/application/Espo/Core/Field/Date.php
index a5b54ec7d3..4147395048 100644
--- a/application/Espo/Core/Field/Date.php
+++ b/application/Espo/Core/Field/Date.php
@@ -43,9 +43,9 @@ use Throwable;
  */
 class Date implements DateTimeable
 {
-    private $value;
+    private string $value;
 
-    private $dateTime;
+    private DateTimeImmutable $dateTime;
 
     private const SYSTEM_FORMAT = 'Y-m-d';
 
@@ -138,6 +138,7 @@ class Date implements DateTimeable
      */
     public function modify(string $modifier): self
     {
+        /** @var DateTimeImmutable|false */
         $dateTime = $this->dateTime->modify($modifier);
 
         if (!$dateTime) {
diff --git a/application/Espo/Core/Field/DateTime.php b/application/Espo/Core/Field/DateTime.php
index be4144c4d6..f50055684d 100644
--- a/application/Espo/Core/Field/DateTime.php
+++ b/application/Espo/Core/Field/DateTime.php
@@ -43,9 +43,9 @@ use Throwable;
  */
 class DateTime implements DateTimeable
 {
-    private $value;
+    private string $value;
 
-    private $dateTime;
+    private DateTimeImmutable $dateTime;
 
     private const SYSTEM_FORMAT = 'Y-m-d H:i:s';
 
@@ -170,6 +170,9 @@ class DateTime implements DateTimeable
      */
     public function modify(string $modifier): self
     {
+        /**
+         * @var DateTimeImmutable|false
+         */
         $dateTime = $this->dateTime->modify($modifier);
 
         if (!$dateTime) {
diff --git a/application/Espo/Core/Field/DateTimeOptional.php b/application/Espo/Core/Field/DateTimeOptional.php
index 0bf3f910ac..b39debd80f 100644
--- a/application/Espo/Core/Field/DateTimeOptional.php
+++ b/application/Espo/Core/Field/DateTimeOptional.php
@@ -44,9 +44,9 @@ use RuntimeException;
  */
 class DateTimeOptional implements DateTimeable
 {
-    private $dateTimeValue = null;
+    private ?DateTime $dateTimeValue = null;
 
-    private $dateValue = null;
+    private ?Date $dateValue = null;
 
     private const SYSTEM_FORMAT = 'Y-m-d H:i:s';
 
diff --git a/application/Espo/Core/Field/EmailAddress.php b/application/Espo/Core/Field/EmailAddress.php
index 80d292be38..51a15577ad 100644
--- a/application/Espo/Core/Field/EmailAddress.php
+++ b/application/Espo/Core/Field/EmailAddress.php
@@ -38,11 +38,11 @@ use FILTER_VALIDATE_EMAIL;
  */
 class EmailAddress
 {
-    private $address;
+    private string $address;
 
-    private $isOptedOut = false;
+    private bool $isOptedOut = false;
 
-    private $isInvalid = false;
+    private bool $isInvalid = false;
 
     public function __construct(string $address)
     {
diff --git a/application/Espo/Core/Field/EmailAddress/EmailAddressGroupFactory.php b/application/Espo/Core/Field/EmailAddress/EmailAddressGroupFactory.php
index 1ae9f675e5..c0f9c4c4f3 100644
--- a/application/Espo/Core/Field/EmailAddress/EmailAddressGroupFactory.php
+++ b/application/Espo/Core/Field/EmailAddress/EmailAddressGroupFactory.php
@@ -50,9 +50,9 @@ use RuntimeException;
  */
 class EmailAddressGroupFactory implements ValueFactory
 {
-    private $metadata;
+    private Metadata $metadata;
 
-    private $entityManager;
+    private EntityManager $entityManager;
 
     /**
      * @todo Use OrmDefs instead of Metadata.
@@ -134,6 +134,10 @@ class EmailAddressGroupFactory implements ValueFactory
         return $group;
     }
 
+    /**
+     * @param array<int,array<string,mixed>|\stdClass> $dataList
+     * @return \stdClass[]
+     */
     private function sanitizeDataList(array $dataList): array
     {
         $sanitizedDataList = [];
diff --git a/application/Espo/Core/Field/EmailAddressGroup.php b/application/Espo/Core/Field/EmailAddressGroup.php
index 31773b00e5..2eafac93f2 100644
--- a/application/Espo/Core/Field/EmailAddressGroup.php
+++ b/application/Espo/Core/Field/EmailAddressGroup.php
@@ -40,16 +40,12 @@ class EmailAddressGroup
     /**
      * @var EmailAddress[]
      */
-    private $list = [];
+    private array $list = [];
 
-    /**
-     * @var ?EmailAddress
-     */
-    private $primary = null;
+    private ?EmailAddress $primary = null;
 
     /**
      * @param EmailAddress[] $list
-     *
      * @throws RuntimeException
      */
     public function __construct(array $list = [])
diff --git a/application/Espo/Core/Field/Link.php b/application/Espo/Core/Field/Link.php
index b96f5be810..dd913d301b 100644
--- a/application/Espo/Core/Field/Link.php
+++ b/application/Espo/Core/Field/Link.php
@@ -36,9 +36,9 @@ use RuntimeException;
  */
 class Link
 {
-    private $id;
+    private string $id;
 
-    private $name = null;
+    private ?string $name = null;
 
     public function __construct(string $id)
     {
diff --git a/application/Espo/Core/Field/LinkMultiple/LinkMultipleFactory.php b/application/Espo/Core/Field/LinkMultiple/LinkMultipleFactory.php
index c7e80b9850..ff6b697275 100644
--- a/application/Espo/Core/Field/LinkMultiple/LinkMultipleFactory.php
+++ b/application/Espo/Core/Field/LinkMultiple/LinkMultipleFactory.php
@@ -44,19 +44,13 @@ use Espo\Core\{
 
 use RuntimeException;
 use InvalidArgumentException;
-use StdClass;
+use stdClass;
 
 class LinkMultipleFactory implements ValueFactory
 {
-    /**
-     * @var Defs
-     */
-    private $ormDefs;
+    private Defs $ormDefs;
 
-    /**
-     * @var EntityManager
-     */
-    private $entityManager;
+    private EntityManager $entityManager;
 
     public function __construct(Defs $ormDefs, EntityManager $entityManager)
     {
@@ -124,7 +118,7 @@ class LinkMultipleFactory implements ValueFactory
         return new LinkMultiple($itemList);
     }
 
-    private function loadLinkMultipleField(CoreEntity $entity, $field): void
+    private function loadLinkMultipleField(CoreEntity $entity, string $field): void
     {
         $columns = $this->ormDefs
             ->getEntity($entity->getEntityType())
@@ -134,7 +128,7 @@ class LinkMultipleFactory implements ValueFactory
         $entity->loadLinkMultipleField($field, $columns);
     }
 
-    private function loadColumnData(Entity $entity, string $field): StdClass
+    private function loadColumnData(Entity $entity, string $field): stdClass
     {
         $columnData = (object) [];
 
@@ -172,7 +166,7 @@ class LinkMultipleFactory implements ValueFactory
         return $columnData;
     }
 
-    private function addColumnValues(LinkMultipleItem $item, object $data)
+    private function addColumnValues(LinkMultipleItem $item, stdClass $data): LinkMultipleItem
     {
         foreach (get_object_vars($data) as $column => $value) {
             $item = $item->withColumnValue($column, $value);
diff --git a/application/Espo/Core/Field/LinkMultipleItem.php b/application/Espo/Core/Field/LinkMultipleItem.php
index c151089ec6..79b3556d2a 100644
--- a/application/Espo/Core/Field/LinkMultipleItem.php
+++ b/application/Espo/Core/Field/LinkMultipleItem.php
@@ -36,11 +36,14 @@ use RuntimeException;
  */
 class LinkMultipleItem
 {
-    private $id;
+    private string $id;
 
-    private $name = null;
+    private ?string $name = null;
 
-    private $columnData = [];
+    /**
+     * @var array<string,mixed>
+     */
+    private array $columnData = [];
 
     /**
      * @throws RuntimeException
diff --git a/application/Espo/Core/Field/LinkParent.php b/application/Espo/Core/Field/LinkParent.php
index 9f999f5b34..84ea04b777 100644
--- a/application/Espo/Core/Field/LinkParent.php
+++ b/application/Espo/Core/Field/LinkParent.php
@@ -36,11 +36,11 @@ use RuntimeException;
  */
 class LinkParent
 {
-    private $entityType;
+    private string $entityType;
 
-    private $id;
+    private string $id;
 
-    private $name = null;
+    private ?string $name = null;
 
     public function __construct(string $entityType, string $id)
     {
diff --git a/application/Espo/Core/Field/PhoneNumber.php b/application/Espo/Core/Field/PhoneNumber.php
index d7c994698d..02deb5fd5a 100644
--- a/application/Espo/Core/Field/PhoneNumber.php
+++ b/application/Espo/Core/Field/PhoneNumber.php
@@ -36,13 +36,13 @@ use RuntimeException;
  */
 class PhoneNumber
 {
-    private $number;
+    private string $number;
 
-    private $type = null;
+    private ?string $type = null;
 
-    private $isOptedOut = false;
+    private bool $isOptedOut = false;
 
-    private $isInvalid = false;
+    private bool $isInvalid = false;
 
     public function __construct(string $number)
     {
diff --git a/application/Espo/Core/Field/PhoneNumber/PhoneNumberGroupFactory.php b/application/Espo/Core/Field/PhoneNumber/PhoneNumberGroupFactory.php
index 37633745cb..610817d033 100644
--- a/application/Espo/Core/Field/PhoneNumber/PhoneNumberGroupFactory.php
+++ b/application/Espo/Core/Field/PhoneNumber/PhoneNumberGroupFactory.php
@@ -50,9 +50,9 @@ use RuntimeException;
  */
 class PhoneNumberGroupFactory implements ValueFactory
 {
-    private $metadata;
+    private Metadata $metadata;
 
-    private $entityManager;
+    private EntityManager $entityManager;
 
     /**
      * @todo Use OrmDefs instead of Metadata.
@@ -138,6 +138,10 @@ class PhoneNumberGroupFactory implements ValueFactory
         return $group;
     }
 
+    /**
+     * @param array<int,array<string,mixed>|\stdClass> $dataList
+     * @return \stdClass[]
+     */
     private function sanitizeDataList(array $dataList): array
     {
         $sanitizedDataList = [];
diff --git a/application/Espo/Repositories/PhoneNumber.php b/application/Espo/Repositories/PhoneNumber.php
index d829cf5892..1b917ec046 100644
--- a/application/Espo/Repositories/PhoneNumber.php
+++ b/application/Espo/Repositories/PhoneNumber.php
@@ -38,7 +38,6 @@ use Espo\Core\Repositories\Database;
 use Espo\Core\Di;
 
 /**
- * @template T of PhoneNumberEntity
  * @extends Database<PhoneNumberEntity>
  */
 class PhoneNumber extends Database implements