diff --git a/access/bible.cpp b/access/bible.cpp
index d7597f58b..6405cd368 100644
--- a/access/bible.cpp
+++ b/access/bible.cpp
@@ -23,7 +23,6 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 #include <database/privileges.h>
 #include <client/logic.h>
 #include <filter/roles.h>
-using namespace std;
 
 
 namespace access_bible {
@@ -31,7 +30,7 @@ namespace access_bible {
 
 // Returns true if the $user has read access to the $bible.
 // If no $user is given, it takes the currently logged-in user.
-bool read (Webserver_Request& webserver_request, const string & bible, string user)
+bool read (Webserver_Request& webserver_request, const std::string& bible, std::string user)
 {
   // Client: User has access to all Bibles.
 #ifdef HAVE_CLIENT
@@ -67,7 +66,7 @@ bool read (Webserver_Request& webserver_request, const string & bible, string us
 
   // No Bibles assigned: Consultant can view any Bible.
   if (role_level >= Filter_Roles::consultant ()) {
-    if (int privileges_count = DatabasePrivileges::get_bible_book_count (); privileges_count == 0) {
+    if (const int privileges_count = DatabasePrivileges::get_bible_book_count (); privileges_count == 0) {
       return true;
     }
   }
@@ -79,7 +78,7 @@ bool read (Webserver_Request& webserver_request, const string & bible, string us
 
 
 // Returns true if the user has write access to the $bible.
-bool write (Webserver_Request& webserver_request, const string & bible, string user)
+bool write (Webserver_Request& webserver_request, const std::string& bible, std::string user)
 {
 #ifdef HAVE_CLIENT
   // Client: When not yet connected to the Cloud, the user has access to all Bibles.
@@ -113,7 +112,7 @@ bool write (Webserver_Request& webserver_request, const string & bible, string u
   
   // No Bibles assigned: Translator can write to any bible.
   if (level >= Filter_Roles::translator ()) {
-    if (int privileges_count = DatabasePrivileges::get_bible_book_count (); privileges_count == 0) {
+    if (const int privileges_count = DatabasePrivileges::get_bible_book_count (); privileges_count == 0) {
       return true;
     }
   }
@@ -127,7 +126,7 @@ bool write (Webserver_Request& webserver_request, const string & bible, string u
 // If no user is given, it takes the currently logged-in user.
 // If the user has read-only access to even one book of the $bible,
 // then the user is considered not to have write access to the entire $bible.
-bool book_write (Webserver_Request& webserver_request, string user, const string & bible, int book)
+bool book_write (Webserver_Request& webserver_request, std::string user, const std::string& bible, int book)
 {
 #ifdef HAVE_CLIENT
   // Client: When not yet connected to the Cloud, the user has access to the book.
@@ -164,7 +163,7 @@ bool book_write (Webserver_Request& webserver_request, string user, const string
 
   // No Bibles assigned: Translator can write to any bible.
   if (level >= Filter_Roles::translator ()) {
-    if (int privileges_count = DatabasePrivileges::get_bible_book_count (); privileges_count == 0) {
+    if (const int privileges_count = DatabasePrivileges::get_bible_book_count (); privileges_count == 0) {
       return true;
     }
   }
@@ -176,11 +175,11 @@ bool book_write (Webserver_Request& webserver_request, string user, const string
 
 // Returns an array of Bibles the user has read access to.
 // If no user is given, it takes the currently logged-in user.
-vector <string> bibles (Webserver_Request& webserver_request, string user)
+std::vector <std::string> bibles (Webserver_Request& webserver_request, std::string user)
 {
-  vector <string> allbibles = webserver_request.database_bibles()->get_bibles ();
-  vector <string> bibles;
-  for (auto & bible : allbibles) {
+  std::vector <std::string> allbibles = webserver_request.database_bibles()->get_bibles ();
+  std::vector <std::string> bibles {};
+  for (const auto& bible : allbibles) {
     if (read (webserver_request, bible, user)) {
       bibles.push_back (bible);
     }
@@ -192,11 +191,11 @@ vector <string> bibles (Webserver_Request& webserver_request, string user)
 // This function clamps bible.
 // It returns the $bible if the currently logged-in user has access to it.
 // Else it returns another accessible bible or nothing.
-string clamp (Webserver_Request& webserver_request, string bible)
+std::string clamp (Webserver_Request& webserver_request, std::string bible)
 {
   if (!read (webserver_request, bible)) {
-    bible = string();
-    vector <string> bibles = access_bible::bibles (webserver_request);
+    bible = std::string();
+    std::vector <std::string> bibles = access_bible::bibles (webserver_request);
     if (!bibles.empty ()) bible = bibles [0];
     webserver_request.database_config_user ()->setBible (bible);
   }
@@ -207,17 +206,17 @@ string clamp (Webserver_Request& webserver_request, string bible)
 // This function checks whether the user in the $webserver_request
 // has $read or $write access to one or more Bibles.
 // It returns a tuple <read, write>.
-tuple<bool, bool> any (Webserver_Request& webserver_request)
+std::tuple<bool, bool> any (Webserver_Request& webserver_request)
 {
   bool read {false};
   bool write {false};
-  vector <string> bibles = webserver_request.database_bibles()->get_bibles ();
-  for (auto & bible : bibles) {
+  std::vector <std::string> bibles = webserver_request.database_bibles()->get_bibles ();
+  for (const auto& bible : bibles) {
     if (access_bible::read (webserver_request, bible)) read = true;
     if (access_bible::write (webserver_request, bible)) write = true;
   }
   // The results consists of <read, write>.
-  return make_tuple(read, write);
+  return std::make_tuple(read, write);
 }
 
 
diff --git a/access/logic.cpp b/access/logic.cpp
index 7a4df2e53..00e90db86 100644
--- a/access/logic.cpp
+++ b/access/logic.cpp
@@ -23,7 +23,6 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 #include <filter/roles.h>
 #include <database/privileges.h>
 #include <webserver/request.h>
-using namespace std;
 
 
 namespace access_logic {
@@ -35,7 +34,7 @@ int view_resources_role ()
 }
 
 
-bool privilege_view_resources (Webserver_Request& webserver_request, string user)
+bool privilege_view_resources (Webserver_Request& webserver_request, std::string user)
 {
   int level {0};
   user_level (webserver_request, user, level);
@@ -50,7 +49,7 @@ int view_notes_role ()
 }
 
 
-bool privilege_view_notes (Webserver_Request& webserver_request, string user)
+bool privilege_view_notes (Webserver_Request& webserver_request, std::string user)
 {
   int level {0};
   user_level (webserver_request, user, level);
@@ -65,7 +64,7 @@ int create_comment_notes_role ()
 }
 
 
-bool privilege_create_comment_notes (Webserver_Request& webserver_request, string user)
+bool privilege_create_comment_notes (Webserver_Request& webserver_request, std::string user)
 {
   int level {0};
   user_level (webserver_request, user, level);
@@ -80,7 +79,7 @@ int delete_consultation_notes_role ()
 }
 
 
-bool privilege_delete_consultation_notes (Webserver_Request& webserver_request, string user)
+bool privilege_delete_consultation_notes (Webserver_Request& webserver_request, std::string user)
 {
   int level {0};
   user_level (webserver_request, user, level);
@@ -95,7 +94,7 @@ int use_advanced_mode_role ()
 }
 
 
-bool privilege_use_advanced_mode (Webserver_Request& webserver_request, string user)
+bool privilege_use_advanced_mode (Webserver_Request& webserver_request, std::string user)
 {
   int level {0};
   user_level (webserver_request, user, level);
@@ -110,7 +109,7 @@ int set_stylesheets_role ()
 }
 
 
-bool privilege_set_stylesheets (Webserver_Request& webserver_request, string user)
+bool privilege_set_stylesheets (Webserver_Request& webserver_request, std::string user)
 {
   int level {0};
   user_level (webserver_request, user, level);
@@ -119,7 +118,7 @@ bool privilege_set_stylesheets (Webserver_Request& webserver_request, string use
 }
 
 
-void user_level (Webserver_Request& webserver_request, string & user, int & level)
+void user_level (Webserver_Request& webserver_request, std::string& user, int& level)
 {
   if (user.empty ()) {
     // If no user is given, take the user from the session.
@@ -135,8 +134,8 @@ void user_level (Webserver_Request& webserver_request, string & user, int & leve
 void create_client_files ()
 {
   Database_Users database_users;
-  vector <string> users = database_users.get_users ();
-  for (auto & user : users) {
+  std::vector <std::string> users = database_users.get_users ();
+  for (const auto& user : users) {
     // Only maintain the privilege file if it does not yet exist,
     // to avoid unnecessary downloads by the clients.
     database_privileges_client_create (user, false);
@@ -144,7 +143,7 @@ void create_client_files ()
 }
 
 
-set <string> default_privilege_usernames ()
+std::set <std::string> default_privilege_usernames ()
 {
   return {"defaultguest", "defaultmember", "defaultconsultant", "defaulttranslator", "defaultmanager"};
 }
diff --git a/access/user.cpp b/access/user.cpp
index 82e8eaa15..f89ad0679 100644
--- a/access/user.cpp
+++ b/access/user.cpp
@@ -21,22 +21,21 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 #include <webserver/request.h>
 #include <access/bible.h>
 #include <filter/roles.h>
-using namespace std;
 
 
 // This function returns users assigned to the logged-in user.
-vector <string> access_user::assignees (Webserver_Request& webserver_request)
+std::vector <std::string> access_user::assignees (Webserver_Request& webserver_request)
 {
-  const string myuser = webserver_request.session_logic ()->currentUser ();
+  const std::string myuser = webserver_request.session_logic ()->currentUser ();
   const int mylevel = webserver_request.session_logic ()->currentLevel ();
 
   // This holds the assignees.
-  vector <string> assignees {};
+  std::vector <std::string> assignees {};
 
   // Process all users.
-  vector <string> users = webserver_request.database_users ()->get_users ();
+  std::vector <std::string> users = webserver_request.database_users ()->get_users ();
   sort (users.begin(), users.end());
-  for (const auto & user : users) {
+  for (const auto& user : users) {
     // Assignees should have a level less than or equal to mylevel.
     if (webserver_request.database_users ()->get_level (user) <= mylevel) {
       assignees.push_back (user);