Extend concordance lists

interfaces/MDImporterBlacklistInterface.php

@@ -0,0 +1,21 @@
+<?PHP
+/**
+ * Describes a blacklist for the importer.
+ *
+ * @author Joshua Ramon Enslin <joshua@museum-digital.de>
+ */
+declare(strict_types = 1);
+
+/**
+ * Describes a blacklist for the importer.
+ */
+interface MDImporterBlacklistInterface {
+    /**
+     * Checks if the input string is blacklisted.
+     *
+     * @param string $input Input string.
+     *
+     * @return bool
+     */
+    public static function isBlacklisted(string $input):bool;
+}