diff --git a/.travis.yml b/.travis.yml
index f5af93db2c0..8439c1ba20f 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -2,7 +2,7 @@
 # from Dolibarr GitHub repository.
 # For syntax, see http://about.travis-ci.org/docs/user/languages/php/
 
-# We use dist: trusty to have php 5.4+ available
+# We use dist: xenial to have php 5.6+ available
 dist: xenial
 sudo: required
 
diff --git a/htdocs/install/default.css b/htdocs/install/default.css
index 7a3bb7b3290..ab4e36c9f68 100644
--- a/htdocs/install/default.css
+++ b/htdocs/install/default.css
@@ -16,6 +16,9 @@
  */
 
 
+.opacitymedium {
+	opacity: 0.5;
+}
 
 body {
 	font-size:14px;
diff --git a/htdocs/install/fileconf.php b/htdocs/install/fileconf.php
index b800f5f6ad4..4770575774a 100644
--- a/htdocs/install/fileconf.php
+++ b/htdocs/install/fileconf.php
@@ -136,7 +136,7 @@ if (!empty($force_install_noedit)) {
 			>
 		</td>
 		<td class="comment"><?php
-		print $langs->trans("WithNoSlashAtTheEnd")."<br>";
+		print '<span class="opacitymedium">'.$langs->trans("WithNoSlashAtTheEnd")."</span><br>";
 		print $langs->trans("Examples").":<br>";
 		?>
 		<ul>
@@ -167,7 +167,7 @@ if (!empty($force_install_noedit)) {
 			>
 		</td>
 		<td class="comment"><?php
-		print $langs->trans("WithNoSlashAtTheEnd")."<br>";
+		print '<span class="opacitymedium">'.$langs->trans("WithNoSlashAtTheEnd")."</span><br>";
 		print $langs->trans("DirectoryRecommendation")."<br>";
 		print $langs->trans("Examples").":<br>";
 		?>
diff --git a/htdocs/langs/en_US/install.lang b/htdocs/langs/en_US/install.lang
index 1b173656a47..bf9c08c4ba7 100644
--- a/htdocs/langs/en_US/install.lang
+++ b/htdocs/langs/en_US/install.lang
@@ -91,7 +91,7 @@ GoToSetupArea=Go to Dolibarr (setup area)
 MigrationNotFinished=The database version is not completely up to date: run the upgrade process again.
 GoToUpgradePage=Go to upgrade page again
 WithNoSlashAtTheEnd=Without the slash "/" at the end
-DirectoryRecommendation=It is recommended to use a directory outside of the web pages.
+DirectoryRecommendation=<span class="warning">IMPORTANT</span>: You must use a directory that is outside of the web pages (so do not use a subdirectory of previous parameter).
 LoginAlreadyExists=Already exists
 DolibarrAdminLogin=Dolibarr admin login
 AdminLoginAlreadyExists=Dolibarr administrator account '<b>%s</b>' already exists. Go back if you want to create another one.