diff --git includes/database/mysql/schema.inc includes/database/mysql/schema.inc
index 56fca57..3155eb5 100644
--- includes/database/mysql/schema.inc
+++ includes/database/mysql/schema.inc
@@ -282,10 +282,10 @@ class DatabaseSchema_mysql extends DatabaseSchema {
 
   public function renameTable($table, $new_name) {
     if (!$this->tableExists($table)) {
-      throw new DatabaseSchemaObjectDoesNotExistException(t("Cannot rename %table to %table_new: table %table doesn't exist.", array('%table' => $table, '%table_new' => $new_name)));
+      throw new DatabaseSchemaObjectDoesNotExistException(t("Cannot rename @table to @table_new: table @table doesn't exist.", array('@table' => $table, '@table_new' => $new_name)));
     }
     if ($this->tableExists($new_name)) {
-      throw new DatabaseSchemaObjectExistsException(t("Cannot rename %table to %table_new: table %table_new already exists.", array('%table' => $table, '%table_new' => $new_name)));
+      throw new DatabaseSchemaObjectExistsException(t("Cannot rename @table to @table_new: table @table_new already exists.", array('@table' => $table, '@table_new' => $new_name)));
     }
 
     $info = $this->getPrefixInfo($new_name);
@@ -303,10 +303,10 @@ class DatabaseSchema_mysql extends DatabaseSchema {
 
   public function addField($table, $field, $spec, $keys_new = array()) {
     if (!$this->tableExists($table)) {
-      throw new DatabaseSchemaObjectDoesNotExistException(t("Cannot add field %table.%field: table doesn't exist.", array('%field' => $field, '%table' => $table)));
+      throw new DatabaseSchemaObjectDoesNotExistException(t("Cannot add field @table.@field: table doesn't exist.", array('@field' => $field, '@table' => $table)));
     }
     if ($this->fieldExists($table, $field)) {
-      throw new DatabaseSchemaObjectExistsException(t("Cannot add field %table.%field: field already exists.", array('%field' => $field, '%table' => $table)));
+      throw new DatabaseSchemaObjectExistsException(t("Cannot add field @table.@field: field already exists.", array('@field' => $field, '@table' => $table)));
     }
 
     $fixnull = FALSE;
@@ -372,10 +372,10 @@ class DatabaseSchema_mysql extends DatabaseSchema {
 
   public function addPrimaryKey($table, $fields) {
     if (!$this->tableExists($table)) {
-      throw new DatabaseSchemaObjectDoesNotExistException(t("Cannot add primary key to table %table: table doesn't exist.", array('%table' => $table)));
+      throw new DatabaseSchemaObjectDoesNotExistException(t("Cannot add primary key to table @table: table doesn't exist.", array('@table' => $table)));
     }
     if ($this->indexExists($table, 'PRIMARY')) {
-      throw new DatabaseSchemaObjectExistsException(t("Cannot add primary key to table %table: primary key already exists.", array('%table' => $table)));
+      throw new DatabaseSchemaObjectExistsException(t("Cannot add primary key to table @table: primary key already exists.", array('@table' => $table)));
     }
 
     $this->connection->query('ALTER TABLE {' . $table . '} ADD PRIMARY KEY (' . $this->createKeySql($fields) . ')');
@@ -392,10 +392,10 @@ class DatabaseSchema_mysql extends DatabaseSchema {
 
   public function addUniqueKey($table, $name, $fields) {
     if (!$this->tableExists($table)) {
-      throw new DatabaseSchemaObjectDoesNotExistException(t("Cannot add unique key %name to table %table: table doesn't exist.", array('%table' => $table, '%name' => $name)));
+      throw new DatabaseSchemaObjectDoesNotExistException(t("Cannot add unique key @name to table @table: table doesn't exist.", array('@table' => $table, '@name' => $name)));
     }
     if ($this->indexExists($table, $name)) {
-      throw new DatabaseSchemaObjectExistsException(t("Cannot add unique key %name to table %table: unique key already exists.", array('%table' => $table, '%name' => $name)));
+      throw new DatabaseSchemaObjectExistsException(t("Cannot add unique key @name to table @table: unique key already exists.", array('@table' => $table, '@name' => $name)));
     }
 
     $this->connection->query('ALTER TABLE {' . $table . '} ADD UNIQUE KEY `' . $name . '` (' . $this->createKeySql($fields) . ')');
@@ -412,10 +412,10 @@ class DatabaseSchema_mysql extends DatabaseSchema {
 
   public function addIndex($table, $name, $fields) {
     if (!$this->tableExists($table)) {
-      throw new DatabaseSchemaObjectDoesNotExistException(t("Cannot add index %name to table %table: table doesn't exist.", array('%table' => $table, '%name' => $name)));
+      throw new DatabaseSchemaObjectDoesNotExistException(t("Cannot add index @name to table @table: table doesn't exist.", array('@table' => $table, '@name' => $name)));
     }
     if ($this->indexExists($table, $name)) {
-      throw new DatabaseSchemaObjectExistsException(t("Cannot add index %name to table %table: index already exists.", array('%table' => $table, '%name' => $name)));
+      throw new DatabaseSchemaObjectExistsException(t("Cannot add index @name to table @table: index already exists.", array('@table' => $table, '@name' => $name)));
     }
 
     $this->connection->query('ALTER TABLE {' . $table . '} ADD INDEX `' . $name . '` (' . $this->createKeySql($fields) . ')');
@@ -432,10 +432,10 @@ class DatabaseSchema_mysql extends DatabaseSchema {
 
   public function changeField($table, $field, $field_new, $spec, $keys_new = array()) {
     if (!$this->fieldExists($table, $field)) {
-      throw new DatabaseSchemaObjectDoesNotExistException(t("Cannot change the definition of field %table.%name: field doesn't exist.", array('%table' => $table, '%name' => $field)));
+      throw new DatabaseSchemaObjectDoesNotExistException(t("Cannot change the definition of field @table.@name: field doesn't exist.", array('@table' => $table, '@name' => $field)));
     }
     if (($field != $field_new) && $this->fieldExists($table, $field_new)) {
-      throw new DatabaseSchemaObjectExistsException(t("Cannot rename field %table.%name to %name_new: target field already exists.", array('%table' => $table, '%name' => $field, '%name_new' => $field_new)));
+      throw new DatabaseSchemaObjectExistsException(t("Cannot rename field @table.@name to @name_new: target field already exists.", array('@table' => $table, '@name' => $field, '@name_new' => $field_new)));
     }
 
     $sql = 'ALTER TABLE {' . $table . '} CHANGE `' . $field . '` ' . $this->createFieldSql($field_new, $this->processField($spec));
diff --git includes/database/pgsql/schema.inc includes/database/pgsql/schema.inc
index 44dccdc..efeb4da 100644
--- includes/database/pgsql/schema.inc
+++ includes/database/pgsql/schema.inc
@@ -276,10 +276,10 @@ class DatabaseSchema_pgsql extends DatabaseSchema {
 
   function renameTable($table, $new_name) {
     if (!$this->tableExists($table)) {
-      throw new DatabaseSchemaObjectDoesNotExistException(t("Cannot rename %table to %table_new: table %table doesn't exist.", array('%table' => $table, '%table_new' => $new_name)));
+      throw new DatabaseSchemaObjectDoesNotExistException(t("Cannot rename @table to @table_new: table @table doesn't exist.", array('@table' => $table, '@table_new' => $new_name)));
     }
     if ($this->tableExists($new_name)) {
-      throw new DatabaseSchemaObjectExistsException(t("Cannot rename %table to %table_new: table %table_new already exists.", array('%table' => $table, '%table_new' => $new_name)));
+      throw new DatabaseSchemaObjectExistsException(t("Cannot rename @table to @table_new: table @table_new already exists.", array('@table' => $table, '@table_new' => $new_name)));
     }
 
     // Get the schema and tablename for the old table.
@@ -313,10 +313,10 @@ class DatabaseSchema_pgsql extends DatabaseSchema {
 
   public function addField($table, $field, $spec, $new_keys = array()) {
     if (!$this->tableExists($table)) {
-      throw new DatabaseSchemaObjectDoesNotExistException(t("Cannot add field %table.%field: table doesn't exist.", array('%field' => $field, '%table' => $table)));
+      throw new DatabaseSchemaObjectDoesNotExistException(t("Cannot add field @table.@field: table doesn't exist.", array('@field' => $field, '@table' => $table)));
     }
     if ($this->fieldExists($table, $field)) {
-      throw new DatabaseSchemaObjectExistsException(t("Cannot add field %table.%field: field already exists.", array('%field' => $field, '%table' => $table)));
+      throw new DatabaseSchemaObjectExistsException(t("Cannot add field @table.@field: field already exists.", array('@field' => $field, '@table' => $table)));
     }
 
     $fixnull = FALSE;
@@ -397,10 +397,10 @@ class DatabaseSchema_pgsql extends DatabaseSchema {
 
   public function addPrimaryKey($table, $fields) {
     if (!$this->tableExists($table)) {
-      throw new DatabaseSchemaObjectDoesNotExistException(t("Cannot add primary key to table %table: table doesn't exist.", array('%table' => $table)));
+      throw new DatabaseSchemaObjectDoesNotExistException(t("Cannot add primary key to table @table: table doesn't exist.", array('@table' => $table)));
     }
     if ($this->constraintExists($table, 'pkey')) {
-      throw new DatabaseSchemaObjectExistsException(t("Cannot add primary key to table %table: primary key already exists.", array('%table' => $table)));
+      throw new DatabaseSchemaObjectExistsException(t("Cannot add primary key to table @table: primary key already exists.", array('@table' => $table)));
     }
 
     $this->connection->query('ALTER TABLE {' . $table . '} ADD PRIMARY KEY (' . implode(',', $fields) . ')');
@@ -417,10 +417,10 @@ class DatabaseSchema_pgsql extends DatabaseSchema {
 
   function addUniqueKey($table, $name, $fields) {
     if (!$this->tableExists($table)) {
-      throw new DatabaseSchemaObjectDoesNotExistException(t("Cannot add unique key %name to table %table: table doesn't exist.", array('%table' => $table, '%name' => $name)));
+      throw new DatabaseSchemaObjectDoesNotExistException(t("Cannot add unique key @name to table %table: table doesn't exist.", array('@table' => $table, '@name' => $name)));
     }
     if ($this->constraintExists($table, $name . '_key')) {
-      throw new DatabaseSchemaObjectExistsException(t("Cannot add unique key %name to table %table: unique key already exists.", array('%table' => $table, '%name' => $name)));
+      throw new DatabaseSchemaObjectExistsException(t("Cannot add unique key @name to table %table: unique key already exists.", array('@table' => $table, '@name' => $name)));
     }
 
     $this->connection->query('ALTER TABLE {' . $table . '} ADD CONSTRAINT "' . $this->prefixNonTable($table, $name, 'key') . '" UNIQUE (' . implode(',', $fields) . ')');
@@ -437,10 +437,10 @@ class DatabaseSchema_pgsql extends DatabaseSchema {
 
   public function addIndex($table, $name, $fields) {
     if (!$this->tableExists($table)) {
-      throw new DatabaseSchemaObjectDoesNotExistException(t("Cannot add index %name to table %table: table doesn't exist.", array('%table' => $table, '%name' => $name)));
+      throw new DatabaseSchemaObjectDoesNotExistException(t("Cannot add index @name to table @table: table doesn't exist.", array('@table' => $table, '@name' => $name)));
     }
     if ($this->indexExists($table, $name)) {
-      throw new DatabaseSchemaObjectExistsException(t("Cannot add index %name to table %table: index already exists.", array('%table' => $table, '%name' => $name)));
+      throw new DatabaseSchemaObjectExistsException(t("Cannot add index @name to table @table: index already exists.", array('@table' => $table, '@name' => $name)));
     }
 
     $this->connection->query($this->_createIndexSql($table, $name, $fields));
@@ -457,10 +457,10 @@ class DatabaseSchema_pgsql extends DatabaseSchema {
 
   public function changeField($table, $field, $field_new, $spec, $new_keys = array()) {
     if (!$this->fieldExists($table, $field)) {
-      throw new DatabaseSchemaObjectDoesNotExistException(t("Cannot change the definition of field %table.%name: field doesn't exist.", array('%table' => $table, '%name' => $field)));
+      throw new DatabaseSchemaObjectDoesNotExistException(t("Cannot change the definition of field @table.@name: field doesn't exist.", array('@table' => $table, '@name' => $field)));
     }
     if (($field != $field_new) && $this->fieldExists($table, $field_new)) {
-      throw new DatabaseSchemaObjectExistsException(t("Cannot rename field %table.%name to %name_new: target field already exists.", array('%table' => $table, '%name' => $field, '%name_new' => $field_new)));
+      throw new DatabaseSchemaObjectExistsException(t("Cannot rename field @table.@name to @name_new: target field already exists.", array('@table' => $table, '@name' => $field, '@name_new' => $field_new)));
     }
 
     if (!array_key_exists('size', $spec)) {
diff --git includes/database/schema.inc includes/database/schema.inc
index 012b74a..deab07c 100644
--- includes/database/schema.inc
+++ includes/database/schema.inc
@@ -602,7 +602,7 @@ abstract class DatabaseSchema implements QueryPlaceholderInterface {
    */
   public function createTable($name, $table) {
     if ($this->tableExists($name)) {
-      throw new DatabaseSchemaObjectExistsException(t('Table %name already exists.', array('%name' => $name)));
+      throw new DatabaseSchemaObjectExistsException(t('Table @name already exists.', array('@name' => $name)));
     }
   	$statements = $this->createTableSql($name, $table);
     foreach ($statements as $statement) {
diff --git includes/database/sqlite/schema.inc includes/database/sqlite/schema.inc
index 515fc6a..94b0d32 100644
--- includes/database/sqlite/schema.inc
+++ includes/database/sqlite/schema.inc
@@ -230,10 +230,10 @@ class DatabaseSchema_sqlite extends DatabaseSchema {
 
   public function renameTable($table, $new_name) {
     if (!$this->tableExists($table)) {
-      throw new DatabaseSchemaObjectDoesNotExistException(t("Cannot rename %table to %table_new: table %table doesn't exist.", array('%table' => $table, '%table_new' => $new_name)));
+      throw new DatabaseSchemaObjectDoesNotExistException(t("Cannot rename @table to @table_new: table %table doesn't exist.", array('@table' => $table, '@table_new' => $new_name)));
     }
     if ($this->tableExists($new_name)) {
-      throw new DatabaseSchemaObjectExistsException(t("Cannot rename %table to %table_new: table %table_new already exists.", array('%table' => $table, '%table_new' => $new_name)));
+      throw new DatabaseSchemaObjectExistsException(t("Cannot rename @table to @table_new: table %table_new already exists.", array('@table' => $table, '@table_new' => $new_name)));
     }
 
     $schema = $this->introspectSchema($table);
@@ -276,10 +276,10 @@ class DatabaseSchema_sqlite extends DatabaseSchema {
 
   public function addField($table, $field, $spec, $keys_new = array()) {
     if (!$this->tableExists($table)) {
-      throw new DatabaseSchemaObjectDoesNotExistException(t("Cannot add field %table.%field: table doesn't exist.", array('%field' => $field, '%table' => $table)));
+      throw new DatabaseSchemaObjectDoesNotExistException(t("Cannot add field @table.@field: table doesn't exist.", array('@field' => $field, '@table' => $table)));
     }
     if ($this->fieldExists($table, $field)) {
-      throw new DatabaseSchemaObjectExistsException(t("Cannot add field %table.%field: field already exists.", array('%field' => $field, '%table' => $table)));
+      throw new DatabaseSchemaObjectExistsException(t("Cannot add field @table.@field: field already exists.", array('@field' => $field, '@table' => $table)));
     }
 
     // TODO: $keys_new is not supported yet.
@@ -416,10 +416,10 @@ class DatabaseSchema_sqlite extends DatabaseSchema {
 
   public function changeField($table, $field, $field_new, $spec, $keys_new = array()) {
     if (!$this->fieldExists($table, $field)) {
-      throw new DatabaseSchemaObjectDoesNotExistException(t("Cannot change the definition of field %table.%name: field doesn't exist.", array('%table' => $table, '%name' => $field)));
+      throw new DatabaseSchemaObjectDoesNotExistException(t("Cannot change the definition of field @table.@name: field doesn't exist.", array('@table' => $table, '@name' => $field)));
     }
     if (($field != $field_new) && $this->fieldExists($table, $field_new)) {
-      throw new DatabaseSchemaObjectExistsException(t("Cannot rename field %table.%name to %name_new: target field already exists.", array('%table' => $table, '%name' => $field, '%name_new' => $field_new)));
+      throw new DatabaseSchemaObjectExistsException(t("Cannot rename field @table.@name to @name_new: target field already exists.", array('@table' => $table, '@name' => $field, '@name_new' => $field_new)));
     }
 
     $new_schema = $this->introspectSchema($table);
@@ -439,10 +439,10 @@ class DatabaseSchema_sqlite extends DatabaseSchema {
 
   public function addIndex($table, $name, $fields) {
     if (!$this->tableExists($table)) {
-      throw new DatabaseSchemaObjectDoesNotExistException(t("Cannot add index %name to table %table: table doesn't exist.", array('%table' => $table, '%name' => $name)));
+      throw new DatabaseSchemaObjectDoesNotExistException(t("Cannot add index @name to table @table: table doesn't exist.", array('@table' => $table, '@name' => $name)));
     }
     if ($this->indexExists($table, $name)) {
-      throw new DatabaseSchemaObjectExistsException(t("Cannot add index %name to table %table: index already exists.", array('%table' => $table, '%name' => $name)));
+      throw new DatabaseSchemaObjectExistsException(t("Cannot add index @name to table @table: index already exists.", array('@table' => $table, '@name' => $name)));
     }
 
     $schema['indexes'][$name] = $fields;
@@ -467,10 +467,10 @@ class DatabaseSchema_sqlite extends DatabaseSchema {
 
   public function addUniqueKey($table, $name, $fields) {
     if (!$this->tableExists($table)) {
-      throw new DatabaseSchemaObjectDoesNotExistException(t("Cannot add unique key %name to table %table: table doesn't exist.", array('%table' => $table, '%name' => $name)));
+      throw new DatabaseSchemaObjectDoesNotExistException(t("Cannot add unique key @name to table @table: table doesn't exist.", array('@table' => $table, '@name' => $name)));
     }
     if ($this->indexExists($table, $name)) {
-      throw new DatabaseSchemaObjectExistsException(t("Cannot add unique key %name to table %table: unique key already exists.", array('%table' => $table, '%name' => $name)));
+      throw new DatabaseSchemaObjectExistsException(t("Cannot add unique key @name to table @table: unique key already exists.", array('@table' => $table, '@name' => $name)));
     }
 
     $schema['unique keys'][$name] = $fields;
@@ -491,12 +491,12 @@ class DatabaseSchema_sqlite extends DatabaseSchema {
 
   public function addPrimaryKey($table, $fields) {
     if (!$this->tableExists($table)) {
-      throw new DatabaseSchemaObjectDoesNotExistException(t("Cannot add primary key to table %table: table doesn't exist.", array('%table' => $table)));
+      throw new DatabaseSchemaObjectDoesNotExistException(t("Cannot add primary key to table @table: table doesn't exist.", array('@table' => $table)));
     }
 
     $new_schema = $this->introspectSchema($table);
     if (!empty($new_schema['primary key'])) {
-      throw new DatabaseSchemaObjectExistsException(t("Cannot add primary key to table %table: primary key already exists.", array('%table' => $table)));
+      throw new DatabaseSchemaObjectExistsException(t("Cannot add primary key to table @table: primary key already exists.", array('@table' => $table)));
     }
 
     $new_schema['primary key'] = $fields;