diff --git a/src/Data/QRDataAbstract.php b/src/Data/QRDataAbstract.php
index 4a539a3fc..8f46e28c6 100644
--- a/src/Data/QRDataAbstract.php
+++ b/src/Data/QRDataAbstract.php
@@ -58,9 +58,14 @@ abstract class QRDataAbstract implements QRDataInterface{
 	 */
 	protected array $dcdata;
 
-	/** @var \chillerlan\Settings\SettingsContainerInterface|\chillerlan\QRCode\QROptions */
+	/**
+	 * @var \chillerlan\Settings\SettingsContainerInterface|\chillerlan\QRCode\QROptions
+	 */
 	protected SettingsContainerInterface $options;
 
+	/**
+	 * a BitBuffer instance
+	 */
 	protected BitBuffer $bitBuffer;
 
 	/**
diff --git a/src/Output/QROutputAbstract.php b/src/Output/QROutputAbstract.php
index 77e51dd4d..6f6c72f9d 100644
--- a/src/Output/QROutputAbstract.php
+++ b/src/Output/QROutputAbstract.php
@@ -22,22 +22,52 @@ use function call_user_func, dirname, file_put_contents, get_called_class, in_ar
  */
 abstract class QROutputAbstract implements QROutputInterface{
 
+	/**
+	 * the current size of the QR matrix
+	 *
+	 * @see \chillerlan\QRCode\Data\QRMatrix::size()
+	 */
 	protected int $moduleCount;
 
-	protected QRMatrix $matrix;
-	/** @var \chillerlan\Settings\SettingsContainerInterface|\chillerlan\QRCode\QROptions */
-	protected SettingsContainerInterface $options;
-
+	/**
+	 * the current output mode
+	 *
+	 * @see \chillerlan\QRCode\QROptions::$outputType
+	 */
 	protected string $outputMode;
 
+	/**
+	 * the default output mode of the current output module
+	 */
 	protected string $defaultMode;
 
+	/**
+	 * the current scaling for a QR pixel
+	 *
+	 * @see \chillerlan\QRCode\QROptions::$scale
+	 */
 	protected int $scale;
 
+	/**
+	 * the side length of the QR image (modules * scale)
+	 */
 	protected int $length;
 
+	/**
+	 * an (optional) array of color values for the several QR matrix parts
+	 */
 	protected array $moduleValues;
 
+	/**
+	 * the (filled) data matrix object
+	 */
+	protected QRMatrix $matrix;
+
+	/**
+	 * @var \chillerlan\Settings\SettingsContainerInterface|\chillerlan\QRCode\QROptions
+	 */
+	protected SettingsContainerInterface $options;
+
 	/**
 	 * QROutputAbstract constructor.
 	 */