diff --git a/src/MDNodaRepositoriesSet.php b/src/MDNodaRepositoriesSet.php
index 8d1f81a..960ec1a 100644
--- a/src/MDNodaRepositoriesSet.php
+++ b/src/MDNodaRepositoriesSet.php
@@ -56,6 +56,7 @@ final class MDNodaRepositoriesSet extends MDValueSet {
     public const REPOSITORIES_TAG = [
         'aat',
         'ackerbau',
+        'avefi',
         'allgemein',
         'col',
         'bne',
diff --git a/src/enums/MDNodaRepository.php b/src/enums/MDNodaRepository.php
index ebaf79f..d31c072 100644
--- a/src/enums/MDNodaRepository.php
+++ b/src/enums/MDNodaRepository.php
@@ -14,6 +14,7 @@ enum MDNodaRepository implements MDValueEnumInterface, JsonSerializable {
     case allgemein; // General link to a good source
     case aat;
     case ackerbau;
+    case avefi;
     case bne;
     case bnf;
     case col;
@@ -57,6 +58,7 @@ enum MDNodaRepository implements MDValueEnumInterface, JsonSerializable {
             'AAT-ID',
             'aat'                      => self::aat,
             'ackerbau'                 => self::ackerbau,
+            'avefi'                    => self::avefi,
             'bne'                      => self::bne,
             'bnf'                      => self::bnf,
             'col',
@@ -156,6 +158,7 @@ enum MDNodaRepository implements MDValueEnumInterface, JsonSerializable {
             self::allgemein => 'allgemein', // General link to a good source
             self::aat => 'aat',
             self::ackerbau => 'ackerbau',
+            self::avefi => 'avefi',
             self::bne => 'bne',
             self::bnf => 'bnf',
             self::col => 'col',
@@ -199,6 +202,7 @@ enum MDNodaRepository implements MDValueEnumInterface, JsonSerializable {
             self::allgemein => 'General', // General link to a good source
             self::aat => 'Art & Architecture Thesaurus (AAT)',
             self::ackerbau => 'Ackerbau-Thesaurus',
+            self::avefi => 'AVefi',
             self::bne => 'Biblioteca Nacional de España (BNE)',
             self::bnf => 'Bibliothèque nationale de France (BNF)',
             self::col => 'Catalogue of Life',
@@ -242,6 +246,7 @@ enum MDNodaRepository implements MDValueEnumInterface, JsonSerializable {
             self::allgemein => '',
             self::aat       => 'https://vocab.getty.edu/page/aat/',
             self::ackerbau  => 'https://term.museum-digital.de/ackerbau/tag/',
+            self::avefi     => 'https://hdl.handle.net/',
             self::bne       => 'http://datos.bne.es/persona/',
             self::bnf       => "https://catalogue.bnf.fr/ark:/12148/cb",
             self::col       => 'https://www.catalogueoflife.org/data/taxon/',
@@ -304,6 +309,7 @@ enum MDNodaRepository implements MDValueEnumInterface, JsonSerializable {
             self::allgemein => 'https://www.google.de/search?q=' . urlencode($searchTerm),
             self::aat       => 'https://www.getty.edu/vow/AATServlet?english=N&find=' . urlencode($searchTerm) . '&page=1&note=',
             self::ackerbau  => 'https://term.museum-digital.de/redir.php?search=' . urlencode($searchTerm) . '&kind=tag|ackerbau',
+            self::avefi     => 'https://www.av-efi.net/search?query=' . urlencode($searchTerm),
             self::bne       => 'http://datos.bne.es/persona/' . urlencode($searchTerm),
             self::bnf       => 'https://catalogue.bnf.fr/resultats-auteur.do?nomAuteur=' . urlencode($searchTerm) . '+&filtre=1&pageRech=rau',
             self::col       => 'https://www.catalogueoflife.org/data/search?q=' . urlencode($searchTerm),
@@ -422,6 +428,28 @@ enum MDNodaRepository implements MDValueEnumInterface, JsonSerializable {
 
     }
 
+    /**
+     * Validates an AVefi ID.  AVefi IDs are not numeric.
+     *
+     * @param string   $id       ID to validate.
+     *
+     * @return string|false
+     */
+    private static function validateAvefiId(string $id):string|false {
+
+        if (str_contains($id, 'https://www.av-efi.net/')) {
+            $id = str_replace('https://www.av-efi.net/res/', '', $id);
+        }
+        if (str_contains($id, 'https://hdl.handle.net/')) {
+            $id = str_replace('https://hdl.handle.net/', '', $id);
+        }
+
+        if (substr_count($id, '/') !== 1) return false;
+
+        return $id;
+
+    }
+
     /**
      * Validates a BNE ID, returning a string or false. The BNE is basically equalivalent to the
      * GND, just that the X character can be prepended to the number.
@@ -778,6 +806,7 @@ enum MDNodaRepository implements MDValueEnumInterface, JsonSerializable {
                 'https://vocab.getty.edu/page/aat/',
             ]),
             self::ackerbau  => self::validateNumericId($id, ['https://term.museum-digital.de/ackerbau/tag/']),
+            self::avefi     => self::validateAvefiId($id),
             self::bne       => self::validateBneId($id, ['http://datos.bne.es/persona/', 'https://datos.bne.es/persona/']),
             self::bnf       => self::validateBnfId($id),
             self::col       => self::validateColId($id),
diff --git a/tests/MDNodaRepositoryTest.php b/tests/MDNodaRepositoryTest.php
index f17a586..ae608e8 100644
--- a/tests/MDNodaRepositoryTest.php
+++ b/tests/MDNodaRepositoryTest.php
@@ -48,6 +48,34 @@ final class MDNodaRepositoryTest extends TestCase {
 
     }
 
+    /**
+     * Data provider for validating AVefi IDs.
+     *
+     * @return Generator<string, array{0: string|false, 1: string}>
+     */
+    public static function avefiIdForValidationProvider():Generator {
+
+        yield "Full URL, https" => ["21.11155/D80067AB-B4F5-4139-8D78-540D8BC001B8", "https://www.av-efi.net/res/21.11155/D80067AB-B4F5-4139-8D78-540D8BC001B8"];
+        yield "ID" => ["21.11155/D80067AB-B4F5-4139-8D78-540D8BC001B8", "21.11155/D80067AB-B4F5-4139-8D78-540D8BC001B8"];
+        yield "Broken input / XX503494safdsaf;3" => [false, "XX503494safdsaf;3"];
+
+    }
+
+    /**
+     * Ensure validating references to the AVefi works.
+     *
+     * @param string|false $expected    Expected output.
+     * @param string       $inputString Input string.
+     *
+     * @return void
+     */
+    #[DataProvider('avefiIdForValidationProvider')]
+    public function testAvefiIdValidation(string|false $expected, string $inputString):void {
+
+        self::assertEquals($expected, MDNodaRepository::avefi->validateId($inputString));
+
+    }
+
     /**
      * Data provider for validating BNE IDs.
      *
@@ -62,17 +90,6 @@ final class MDNodaRepositoryTest extends TestCase {
 
     }
 
-    /**
-     * Data provider for validating BNE IDs.
-     *
-     * @return Generator<string, array{0: string|false, 1: string}>
-     */
-    public static function bnfIdForValidationProvider():Generator {
-
-        yield "Broken input / duplicate https" => [false, "https://catalogue.bnf.fr/ark:/12148/cbhttps://catalogue.bnf.fr/ark:/12148/cbhttps://catalogue.bnf.fr/ark:/12148/cb104183522"];
-
-    }
-
     /**
      * Ensure validating references to the BNE works.
      *
@@ -88,6 +105,17 @@ final class MDNodaRepositoryTest extends TestCase {
 
     }
 
+    /**
+     * Data provider for validating BNE IDs.
+     *
+     * @return Generator<string, array{0: string|false, 1: string}>
+     */
+    public static function bnfIdForValidationProvider():Generator {
+
+        yield "Broken input / duplicate https" => [false, "https://catalogue.bnf.fr/ark:/12148/cbhttps://catalogue.bnf.fr/ark:/12148/cbhttps://catalogue.bnf.fr/ark:/12148/cb104183522"];
+
+    }
+
     /**
      * Data provider for validating GND IDs.
      *