diff --git a/app/Generator/Chart/Basic/GeneratorInterface.php b/app/Generator/Chart/Basic/GeneratorInterface.php
index 92b1b29d93..31deeb0a30 100644
--- a/app/Generator/Chart/Basic/GeneratorInterface.php
+++ b/app/Generator/Chart/Basic/GeneratorInterface.php
@@ -22,10 +22,15 @@ interface GeneratorInterface
 {
 
     /**
-     * Will generate a (ChartJS) compatible array from the given input. Expects this format:
+     * Will generate a Chart JS compatible array from the given input. Expects this format
+     *
+     * Will take labels for all from first set.
      *
      * 0: [
      *    'label' => 'label of set',
+     *    'type' => bar or line, optional
+     *    'yAxisID' => ID of yAxis, optional, will not be included when unused.
+     *    'fill' => if to fill a line? optional, will not be included when unused.
      *    'entries' =>
      *        [
      *         'label-of-entry' => 'value'
@@ -33,12 +38,16 @@ interface GeneratorInterface
      *    ]
      * 1: [
      *    'label' => 'label of another set',
+     *    'type' => bar or line, optional
+     *    'yAxisID' => ID of yAxis, optional, will not be included when unused.
+     *    'fill' => if to fill a line? optional, will not be included when unused.
      *    'entries' =>
      *        [
      *         'label-of-entry' => 'value'
      *        ]
      *    ]
      *
+     * @SuppressWarnings(PHPMD.CyclomaticComplexity) // it's five.
      *
      * @param array $data
      *