diff --git a/swad_constant.c b/swad_constant.c
new file mode 100644
index 000000000..87961205c
--- /dev/null
+++ b/swad_constant.c
@@ -0,0 +1,72 @@
+// swad_constant.c: common constants used in several modules
+
+/*
+    SWAD (Shared Workspace At a Distance),
+    is a web platform developed at the University of Granada (Spain),
+    and used to support university teaching.
+
+    This file is part of SWAD core.
+    Copyright (C) 1999-2023 Antonio Caņas Vargas
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as
+    published by the Free Software Foundation, either version 3 of the
+    License, or (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+/*****************************************************************************/
+/*********************************** Headers *********************************/
+/*****************************************************************************/
+
+#include "swad_constant.h"
+
+/*****************************************************************************/
+/***************************** Public constants ******************************/
+/*****************************************************************************/
+
+const char *Cns_ParShrtOrFullName[Cns_NUM_SHRT_FULL_NAMES] =
+  {
+   [Cns_SHRT_NAME] = "ShortName",
+   [Cns_FULL_NAME] = "FullName",
+  };
+const char *Cns_FldShrtOrFullName[Cns_NUM_SHRT_FULL_NAMES] =
+  {
+   [Cns_SHRT_NAME] = "ShortName",
+   [Cns_FULL_NAME] = "FullName",
+  };
+unsigned Cns_MaxBytesShrtOrFullName[Cns_NUM_SHRT_FULL_NAMES] =
+  {
+   [Cns_SHRT_NAME] = Cns_MAX_BYTES_SHRT_NAME,
+   [Cns_FULL_NAME] = Cns_MAX_BYTES_FULL_NAME,
+  };
+
+/*****************************************************************************/
+/**************************** Private constants ******************************/
+/*****************************************************************************/
+
+/*****************************************************************************/
+/******************************* Private types *******************************/
+/*****************************************************************************/
+
+/*****************************************************************************/
+/************** External global variables from others modules ****************/
+/*****************************************************************************/
+
+/*****************************************************************************/
+/************************** Public global variables **************************/
+/*****************************************************************************/
+
+/*****************************************************************************/
+/************************* Private global variables **************************/
+/*****************************************************************************/
+
+/*****************************************************************************/
+/***************************** Private prototypes ****************************/
+/*****************************************************************************/