Changed the way that notable attributes are worked out to make better sense, and updated the readme

README.md

@@ -164,7 +164,7 @@ Here's a helpful table showing what PaperTrail stores:
 PaperTrail stores the values in the Model Before column.  Most other auditing/versioning plugins store the After column.
 
 
-## Ignoring changes to certain attributes
+## Choosing Attributes To Monitor
 
 You can ignore changes to certain attributes like this:
 
@@ -182,6 +182,22 @@ This means that changes to just the `title` or `rating` will not store another v
     >> a.versions.length                         # 2
     >> a.versions.last.reify.title               # 'My Title'
 
+Or, you can specify a list of all attributes you care about:
+
+    class Article < ActiveRecord::Base
+      has_paper_trail :only => [:title]
+    end
+
+This means that only changes to the `title` will save a version of the article:
+
+	>> a = Article.create
+    >> a.versions.length                         # 1
+    >> a.update_attributes :title => 'My Title'
+    >> a.versions.length                         # 2
+    >> a.update_attributes :content => 'Hello'
+    >> a.versions.length                         # 2
+    
+Passing both `:ignore` and `:only` options will result in the article being saved if a changed attribute is included in `:only` but not in `:ignore`.
 
 ## Reverting And Undeleting A Model
 

lib/paper_trail/has_paper_trail.rb

@@ -151,7 +151,11 @@ module PaperTrail
       end
 
       def notably_changed
-        self.class.only.empty? ? (changed - self.class.ignore) : (changed & self.class.only)
+        self.class.only.empty? ? changed_and_not_ignored : (changed_and_not_ignored & self.class.only)
+      end
+      
+      def changed_and_not_ignored
+        changed - self.class.ignore
       end
 
       # Returns `true` if PaperTrail is globally enabled and active for this class,