2 files changed, 31 insertions, 4 deletions
diff --git a/guides/source/asset_pipeline.md b/guides/source/asset_pipeline.md
index 39448e92d5..77189e1442 100644
--- a/guides/source/asset_pipeline.md
+++ b/guides/source/asset_pipeline.md
@@ -577,6 +577,33 @@ would generate this HTML:
 
 The `body` param is required by Sprockets.
 
+### Runtime Error Checking
+
+By default the asset pipeline will check for potential errors in development mode during
+runtime. To disable this behavior you can set:
+
+```ruby
+config.assets.raise_runtime_errors = false
+```
+
+When `raise_runtime_errors` is set to `false` sprockets will not check that dependencies of assets are declared properly. Here is a scenario where you must tell the asset pipeline about a dependency:
+
+If you have `application.css.erb` that references `logo.png` like this:
+
+```css
+#logo { background: url(<%= asset_data_uri 'logo.png' %>) }
+```
+
+Then you must declare that `logo.png` is a dependency of `application.css.erb`, so when the image gets re-compiled, the css file does as well. You can do this using the `//= depend_on_asset` declaration:
+
+```css
+//= depend_on_asset "logo.png"
+#logo { background: url(<%= asset_data_uri 'logo.png' %>) }
+```
+
+Without this declaration you may experience strange behavior when pushing to production that is difficult to debug. When you have `raise_runtime_errors` set to `true`, dependencies will be checked at runtime so you can ensure that all dependencies are met.
+
+
 ### Turning Debugging Off
 
 You can turn off debug mode by updating `config/environments/development.rb` to
diff --git a/guides/source/migrations.md b/guides/source/migrations.md
index 71a177bca7..5d5c2724b1 100644
--- a/guides/source/migrations.md
+++ b/guides/source/migrations.md
@@ -297,10 +297,10 @@ You can append as many column name/type pairs as you want.
 You can also specify some options just after the field type between curly
 braces. You can use the following modifiers:
 
-* `limit`        Sets the maximum size of the `string/text/binary/integer` fields
-* `precision`    Defines the precision for the `decimal` fields
-* `scale`        Defines the scale for the `decimal` fields
-* `polymorphic`  Adds a `type` column for `belongs_to` associations
+* `limit`        Sets the maximum size of the `string/text/binary/integer` fields.
+* `precision`    Defines the precision for the `decimal` fields, representing the total number of digits in the number.
+* `scale`        Defines the scale for the `decimal` fields, representing the number of digits after the decimal point.
+* `polymorphic`  Adds a `type` column for `belongs_to` associations.
 * `null`         Allows or disallows `NULL` values in the column.
 
 For instance, running: