diff --git a/core/lib/Drupal/Core/Database/Query/SelectInterface.php b/core/lib/Drupal/Core/Database/Query/SelectInterface.php
index 8e1c757..0d651a6 100644
--- a/core/lib/Drupal/Core/Database/Query/SelectInterface.php
+++ b/core/lib/Drupal/Core/Database/Query/SelectInterface.php
@@ -216,7 +216,9 @@ public function addExpression($expression, $alias = NULL, $arguments = array());
    * This method is a convenience method for innerJoin().
    *
    * @param $table
-   *   The table against which to join.
+   *   The table against which to join. May be a string or another SelectQuery
+   *   object. If a query object is passed, it will be used as a subselect.
+   *   Using a dot in the table name disables prefixing.
    * @param $alias
    *   The alias for the table. In most cases this should be the first letter
    *   of the table, or the first letter of each "word" in the table.
@@ -239,7 +241,9 @@ public function join($table, $alias = NULL, $condition = NULL, $arguments = arra
    * Inner Join against another table in the database.
    *
    * @param $table
-   *   The table against which to join.
+   *   The table against which to join. May be a string or another SelectQuery
+   *   object. If a query object is passed, it will be used as a subselect.
+   *   Using a dot in the table name disables prefixing.
    * @param $alias
    *   The alias for the table. In most cases this should be the first letter
    *   of the table, or the first letter of each "word" in the table.
@@ -262,7 +266,9 @@ public function innerJoin($table, $alias = NULL, $condition = NULL, $arguments =
    * Left Outer Join against another table in the database.
    *
    * @param $table
-   *   The table against which to join.
+   *   The table against which to join. May be a string or another SelectQuery
+   *   object. If a query object is passed, it will be used as a subselect.
+   *   Using a dot in the table name disables prefixing.
    * @param $alias
    *   The alias for the table. In most cases this should be the first letter
    *   of the table, or the first letter of each "word" in the table.
@@ -285,7 +291,9 @@ public function leftJoin($table, $alias = NULL, $condition = NULL, $arguments =
    * Right Outer Join against another table in the database.
    *
    * @param $table
-   *   The table against which to join.
+   *   The table against which to join. May be a string or another SelectQuery
+   *   object. If a query object is passed, it will be used as a subselect.
+   *   Using a dot in the table name disables prefixing.
    * @param $alias
    *   The alias for the table. In most cases this should be the first letter
    *   of the table, or the first letter of each "word" in the table.
@@ -316,6 +324,7 @@ public function rightJoin($table, $alias = NULL, $condition = NULL, $arguments =
    * @param $table
    *   The table against which to join. May be a string or another SelectQuery
    *   object. If a query object is passed, it will be used as a subselect.
+   *   Using a dot in the table name disables prefixing.
    * @param $alias
    *   The alias for the table. In most cases this should be the first letter
    *   of the table, or the first letter of each "word" in the table. If omitted,