diff --git a/includes/class-classifier.php b/includes/class-classifier.php
index 4eaaf13..63c6860 100644
--- a/includes/class-classifier.php
+++ b/includes/class-classifier.php
@@ -226,6 +226,7 @@ final class Classifier
      * shape). Deeper nesting is intentionally NOT supported.
      *
      * @param array<string,string|string[]> $fields CF7 posted_data
+     * @return bool True if any value contains a syntactically valid email
      */
     public static function has_valid_email_anywhere(array $fields): bool
     {
@@ -252,7 +253,10 @@ final class Classifier
      * the value-based heuristic in FieldDetector::find_name(). Returns false if no name
      * field is present (i.e. forms without a name field are immune to this rule).
      *
+     * Cyrillic look-alikes (e.g. 'ОВ') are rejected because the regex is byte-range.
+     *
      * @param array<string,string|string[]> $fields CF7 posted_data
+     * @return bool True if a name field exists and is 1-3 ASCII alphanumeric chars
      */
     public static function has_short_latin_name(array $fields): bool
     {
diff --git a/tests/ClassifierDropTest.php b/tests/ClassifierDropTest.php
index 6b91278..ff77f92 100644
--- a/tests/ClassifierDropTest.php
+++ b/tests/ClassifierDropTest.php
@@ -81,4 +81,25 @@ final class ClassifierDropTest extends Cf7stgTestCase
         $fields = ['text-211' => 'XY', 'text-212' => '+79991234567'];
         self::assertTrue(Classifier::has_short_latin_name($fields));
     }
+
+    public function test_has_short_latin_name_true_for_single_letter_boundary(): void
+    {
+        // Lower boundary of {1,3}: 1 char accepted
+        $fields = ['your-name' => 'A'];
+        self::assertTrue(Classifier::has_short_latin_name($fields));
+    }
+
+    public function test_has_short_latin_name_false_for_four_letters_boundary(): void
+    {
+        // Upper boundary of {1,3}: 4 chars rejected
+        $fields = ['your-name' => 'ABCD'];
+        self::assertFalse(Classifier::has_short_latin_name($fields));
+    }
+
+    public function test_has_short_latin_name_false_for_array_value_with_space_join(): void
+    {
+        // pick_field joins array values with a space → "OB MU" is 5 chars → no false positive.
+        $fields = ['your-name' => ['OB', 'MU']];
+        self::assertFalse(Classifier::has_short_latin_name($fields));
+    }
 }