diff --git a/Models/Guidelines/GS1Datamatrix.php b/Models/Guidelines/GS1Datamatrix.php
index 8ba4adf..2512f70 100644
--- a/Models/Guidelines/GS1Datamatrix.php
+++ b/Models/Guidelines/GS1Datamatrix.php
@@ -550,6 +550,13 @@ class GS1Datamatrix
 
     public array $data = [];
 
+    /**
+     * Validate GS1 data
+     *
+     * @return bool
+     *
+     * @since 1.0.0
+     */
     public function validate() : bool
     {
         if (empty($this->data['01'] ?? '')) {
@@ -565,6 +572,13 @@ class GS1Datamatrix
         return true;
     }
 
+    /**
+     * Render GS1 string representation
+     *
+     * @return string
+     *
+     * @since 1.0.0
+     */
     public function renderString() : string
     {
         $text = '';
@@ -576,6 +590,13 @@ class GS1Datamatrix
         return $text;
     }
 
+    /**
+     * Render internal GS1 string used for datamatrix etc.
+     *
+     * @return string
+     *
+     * @since 1.0.0
+     */
     public function renderCodeString() : string
     {
         // 232 = FNC1 = ]C1
diff --git a/Models/Label.php b/Models/Label.php
index 7114187..34f8f22 100644
--- a/Models/Label.php
+++ b/Models/Label.php
@@ -34,6 +34,13 @@ class Label
 
     public array $elements = [];
 
+    /**
+     * Render label
+     *
+     * @return null|\GdImage
+     *
+     * @since 1.0.0
+     */
     public function render() : ?\GdImage
     {
         $im = \imagecreatetruecolor((int) (37.8 * $this->width), (int) (37.8 * $this->height));
@@ -58,6 +65,7 @@ class Label
         foreach ($this->elements as $element) {
             $color = 0;
 
+            // @todo: replace int type with enum
             if ($element instanceof Shape) {
                 if ($element->type === 1) {
                     // Line
@@ -88,9 +96,9 @@ class Label
                             $bg
                         );
                     }
-                } elseif ($element->type === 3) {
-                } elseif ($element->type === 4) {
                 }
+
+                // @todo: implement circle + elipse
             } elseif ($element instanceof Text) {
                 \imagettftext($im, $element->size, 0, $element->x, $element->y, $color, $element->font, $element->text);
             } elseif ($element instanceof Image) {