reverted:
--- b/core/modules/node/node.api.php
+++ a/core/modules/node/node.api.php
@@ -27,8 +27,7 @@
  * module; it is common to use role IDs as grant IDs, but that is not required.
  * Your module could instead maintain its own list of users, where each list has
  * an ID. In that case, the return value of this hook would be an array of the
+ * list IDs that this user is a member of.
- * list IDs that this user is a member of. 'all' is a reserved realm and can't
- * be used.
  *
  * A node access module may implement as many realms as necessary to properly
  * define the access privileges for the nodes. Note that the system makes no