Document :skip option.

README.md

@@ -215,6 +215,14 @@ This means that only changes to the `title` will save a version of the article:
 
 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`.
 
+You can skip fields altogether with the `:skip` option.  As with `:ignore`, updates to these fields will not create a new `Version`.  In addition, these fields will not be included in the serialised version of the object whenever a new `Version` is created.
+
+For example:
+
+    class Article < ActiveRecord::Base
+      has_paper_trail :skip => [:file_upload]
+    end
+
 
 ## Reverting And Undeleting A Model
 

lib/paper_trail/has_paper_trail.rb

@@ -16,6 +16,9 @@ module PaperTrail
       # :class_name   the name of a custom Version class.  This class should inherit from Version.
       # :ignore       an array of attributes for which a new `Version` will not be created if only they change.
       # :only         inverse of `ignore` - a new `Version` will be created only for these attributes if supplied
+      # :skip         fields to ignore completely.  As with `ignore`, updates to these fields will not create
+      #               a new `Version`.  In addition, these fields will not be included in the serialized versions
+      #               of the object whenever a new `Version` is created.
       # :meta         a hash of extra data to store.  You must add a column to the `versions` table for each key.
       #               Values are objects or procs (which are called with `self`, i.e. the model with the paper
       #               trail).  See `PaperTrail::Controller.info_for_paper_trail` for how to store data from