diff --git a/htdocs/core/modules/printing/printgcp.modules.php b/htdocs/core/modules/printing/printgcp.modules.php
index eeef6ab34e5..6d842244fbf 100644
--- a/htdocs/core/modules/printing/printgcp.modules.php
+++ b/htdocs/core/modules/printing/printgcp.modules.php
@@ -37,6 +37,10 @@ class printing_printgcp extends PrintingDriver
 {
     public $name = 'printgcp';
     public $desc = 'PrintGCPDesc';
+    
+    /**
+     * @var string String with name of icon for myobject. Must be the part after the 'object_' into object_myobject.png
+     */
     public $picto = 'printer';
     public $active = 'PRINTING_PRINTGCP';
     public $conf = array();
diff --git a/htdocs/core/modules/printing/printipp.modules.php b/htdocs/core/modules/printing/printipp.modules.php
index 1d76fe6f574..9b67ea05c1e 100644
--- a/htdocs/core/modules/printing/printipp.modules.php
+++ b/htdocs/core/modules/printing/printipp.modules.php
@@ -32,6 +32,10 @@ class printing_printipp extends PrintingDriver
 {
     public $name = 'printipp';
     public $desc = 'PrintIPPDesc';
+    
+    /**
+     * @var string String with name of icon for myobject. Must be the part after the 'object_' into object_myobject.png
+     */
     public $picto = 'printer';
     public $active = 'PRINTING_PRINTIPP';
     public $conf = array();