2 files changed, 16 insertions, 2 deletions
diff --git a/activerecord/lib/active_record/validations.rb b/activerecord/lib/active_record/validations.rb
index 26c1a9db93..c192e02660 100644
--- a/activerecord/lib/active_record/validations.rb
+++ b/activerecord/lib/active_record/validations.rb
@@ -1,5 +1,5 @@
 module ActiveRecord
-  # = Active Record Validations
+  # = Active Record RecordInvalid
   #
   # Raised by <tt>save!</tt> and <tt>create!</tt> when the record is invalid.  Use the
   # +record+ method to retrieve the record which did not validate.
@@ -18,6 +18,13 @@ module ActiveRecord
     end
   end
 
+  # = Active Record Validations
+  #
+  # Active Record includes the majority of its validations from ActiveModel::Validations
+  # all of which accept the <tt>:on</tt> argument to define the context where the
+  # validations are active. Active Record will always supply either the context of
+  # <tt>:create</tt> or <tt>:update</tt> dependent on whether the model is a
+  # <tt>new_record?</tt>.
   module Validations
     extend ActiveSupport::Concern
     include ActiveModel::Validations
@@ -50,6 +57,13 @@ module ActiveRecord
     end
 
     # Runs all the specified validations and returns true if no errors were added otherwise false.
+    #
+    # ==== Arguments
+    #
+    # * <tt>context</tt> - Context to scope the execution of the validations. Default is <tt>nil</tt>.
+    #   If <tt>nil</tt> then the response of <tt>new_record?</tt> will determine the context. If <tt>new_record?</tt>
+    #   returns true the the context will be <tt>:create</tt>, otherwise <tt>:update</tt>.  Validation contexts
+    #   for each validation can be defined using the <tt>:on</tt> option
     def valid?(context = nil)
       context ||= (new_record? ? :create : :update)
       output = super(context)
diff --git a/activerecord/lib/active_record/validations/associated.rb b/activerecord/lib/active_record/validations/associated.rb
index 183acd73b8..0f5f2a6e99 100644
--- a/activerecord/lib/active_record/validations/associated.rb
+++ b/activerecord/lib/active_record/validations/associated.rb
@@ -33,7 +33,7 @@ module ActiveRecord
       #
       # Configuration options:
       # * <tt>:message</tt> - A custom error message (default is: "is invalid")
-      # * <tt>:on</tt> - Specifies when this validation is active (default is <tt>:save</tt>, other options <tt>:create</tt>, <tt>:update</tt>).
+      # * <tt>:on</tt> - Specifies when this validation is active (default is <tt>nil</tt>, other options <tt>:create</tt>, <tt>:update</tt>).
       # * <tt>:if</tt> - Specifies a method, proc or string to call to determine if the validation should
       #   occur (e.g. <tt>:if => :allow_validation</tt>, or <tt>:if => Proc.new { |user| user.signup_step > 2 }</tt>).  The
       #   method, proc or string should return or evaluate to a true or false value.