diff --git a/history.textile b/history.textile
index 76c72347..94b33fdb 100644
--- a/history.textile
+++ b/history.textile
@@ -1,5 +1,9 @@
 h2. Upcoming Version.
 
+h2. Version 1.6.6
+
+* hanke: Experimental @plausible?@ feature. Checks if the given number is a plausible number. Returns @false@ if 100% not plausible, @true@ if probably true.
+
 h2. Version 1.6.5
 
 * hanke: Ghana (thanks jschwertfeger!).
diff --git a/lib/phony.rb b/lib/phony.rb
index 4e102673..d86ea9b3 100644
--- a/lib/phony.rb
+++ b/lib/phony.rb
@@ -12,6 +12,8 @@
 require File.expand_path '../phony/national_code', __FILE__
 require File.expand_path '../phony/country', __FILE__
 require File.expand_path '../phony/country_codes', __FILE__
+require File.expand_path '../phony/validator', __FILE__
+require File.expand_path '../phony/validators', __FILE__
 require File.expand_path '../phony/dsl', __FILE__
 
 # Countries.
@@ -37,7 +39,8 @@ module Phony
 
   # Phony uses a single country codes instance.
   #
-  @codes = CountryCodes.instance
+  @codes     = CountryCodes.instance
+  @validator = Validators.instance 
 
   class << self
 
@@ -74,6 +77,16 @@ def format! phone_number, options = {}
     end
     alias formatted  format
     alias formatted! format!
+    
+    # Makes a plausibility check.
+    #
+    # If it returns false, it is not plausible.
+    # If it returns true, it is unclear whether it is plausible,
+    # leaning towards being plausible.
+    #
+    def plausible? number, hints = {}
+      @validator.plausible? number, hints
+    end
 
     # def service? number
     #   @codes.service? number.dup
diff --git a/lib/phony/countries.rb b/lib/phony/countries.rb
index c02f2c23..07b2c3a6 100644
--- a/lib/phony/countries.rb
+++ b/lib/phony/countries.rb
@@ -27,7 +27,9 @@
 
   # USA, Canada, etc.
   #
-  country '1', fixed(3) >> split(3,4)
+  country '1',
+          fixed(3) >> split(3,4),
+          invalid_ndcs(/911/)
 
   # Kazakhstan (Republic of) & Russian Federation.
   #
diff --git a/lib/phony/country_codes.rb b/lib/phony/country_codes.rb
index 946845e4..d5c2fd43 100644
--- a/lib/phony/country_codes.rb
+++ b/lib/phony/country_codes.rb
@@ -6,7 +6,7 @@ module Phony
   #
   class CountryCodes
 
-    attr_reader   :mapping
+    attr_reader   :splitter_mapping
     attr_accessor :international_absolute_format, :international_relative_format, :national_format
 
     def initialize
@@ -22,11 +22,14 @@ def self.instance
       @instance ||= new
     end
 
-    @@normalizing_pattern = /^0+|\D/
-    def normalize number
+    @@basic_normalizing_pattern = /^0+|\D/
+    def clean number
       # Remove non-digit chars.
       #
-      number.gsub! @@normalizing_pattern, EMPTY_STRING
+      number.gsub! @@basic_normalizing_pattern, EMPTY_STRING
+    end
+    def normalize number
+      clean number
       national_handler, cc, rest = split_cc number
       @normalize_format % [cc, national_handler.normalize(rest)]
     end
@@ -102,7 +105,7 @@ def split_cc rest
       presumed_cc = ''
       1.upto(3) do |i|
         presumed_cc << rest.slice!(0..0)
-        national_code_handler = mapping[i][presumed_cc]
+        national_code_handler = splitter_mapping[i][presumed_cc]
         return [national_code_handler, presumed_cc, rest] if national_code_handler
       end
       # This line is never reached as CCs are in prefix code.
@@ -121,9 +124,9 @@ def add country_code, country
       country_code = country_code.to_s
       optimized_country_code_access = country_code.size
 
-      @mapping ||= {}
-      @mapping[optimized_country_code_access] ||= {}
-      @mapping[optimized_country_code_access][country_code] = country
+      @splitter_mapping ||= {}
+      @splitter_mapping[optimized_country_code_access] ||= {}
+      @splitter_mapping[optimized_country_code_access][country_code] = country
     end
 
   end
diff --git a/lib/phony/dsl.rb b/lib/phony/dsl.rb
index 415a95cf..6d1e49a7 100644
--- a/lib/phony/dsl.rb
+++ b/lib/phony/dsl.rb
@@ -46,8 +46,9 @@ class DSL
 
     #
     #
-    def country country_code, country
+    def country country_code, country, validator = nil
       Phony::CountryCodes.instance.add country_code, country
+      Phony::Validators.instance.add country_code, validator if validator
     end
 
     # National matcher & splitters.
@@ -89,6 +90,12 @@ def split *local
     def matched_split options = {}
       Phony::LocalSplitters::Regex.instance_for options
     end
+    
+    # Validators
+    #
+    def invalid_ndcs ndc
+      Validator.new.ndc_check ndc
+    end
 
   end
 
diff --git a/lib/phony/validator.rb b/lib/phony/validator.rb
index 0e7c3c9c..81667741 100644
--- a/lib/phony/validator.rb
+++ b/lib/phony/validator.rb
@@ -1,62 +1,24 @@
-# # Number: A possible phone number, E164 or not.
-# # Hints: Information that helps or constricts the plausibility check.
-# #
-# plausible? number, hints = {}
-#
-
-# plausible? number # Uses the definitions from the country definition to plausibility check.
-# plausible? number, cc: 1 # => Checks cc.
-# plausible? number, pattern: /[^5]/ # Uses def, checks against split.
-# plausible? number, country: 1, pattern: [3, 4, 3] # Uses given country – adds cc.
-#
-
-# Basic plausibility is:
-# * Max digits are 15.
-# * Min digits are 2 (?)
-#
-
 module Phony
   
   class Validator
-    
-    # TODO Beautify.
-    #
-    def plausible? number, hints = {}
-      normalized = normalize number
-      
-      # False if it fails the basic check.
-      #
-      return false unless normalized.size === (2..15)
-      
-      # Hint based checking.
-      #
-      cc, ndc, *rest = split normalized
-      
-      # CC.
-      #
-      cc_needed = hints[:cc]
-      return false if cc_needed && cc_needed != cc
-      
-      # NDC.
-      #
-      ndc_needed = hints[:ndc]
-      return false if ndc_needed && ndc_needed != ndc
-      
-      # Country specific checks?
-      #
-      
-      # Get the country.
-      #
-      
-      # Check.
-      #
+  
+    attr_reader :ndc_checks 
+  
+    def initialize
+      @ndc_checks = []
+    end
+  
+    def plausible? ndc, rest
+      ndc_checks && ndc_checks.each do |ndc_check|
+        return false if ndc_check === ndc
+      end
       
-    rescue StandardError
-      return false
+      true
     end
-    
-    def normalize number
-      number
+  
+    def ndc_check ndc
+      @ndc_checks << ndc
+      self
     end
     
   end
diff --git a/lib/phony/validators.rb b/lib/phony/validators.rb
new file mode 100644
index 00000000..19b01923
--- /dev/null
+++ b/lib/phony/validators.rb
@@ -0,0 +1,77 @@
+# # Number: A possible phone number, E164 or not.
+# # Hints: Information that helps or constricts the plausibility check.
+# #
+# plausible? number, hints = {}
+#
+
+# plausible? number # Uses the definitions from the country definition to plausibility check.
+# plausible? number, cc: 1 # => Checks cc.
+# plausible? number, pattern: /[^5]/ # Uses def, checks against split.
+# plausible? number, country: 1, pattern: [3, 4, 3] # Uses given country – adds cc.
+#
+
+# Basic plausibility is:
+# * Max digits are 15.
+# * Min digits are 2 (?)
+#
+
+module Phony
+  
+  class Validators
+    
+    def initialize
+      @validators = {}
+    end
+    
+    def self.instance
+      @instance ||= new
+    end
+    
+    # Add a specific country validator.
+    #
+    def add cc, validator
+      @validators[cc] = validator
+    end
+    
+    # Is the given number plausible?
+    #
+    def plausible? number, hints = {}
+      normalized = CountryCodes.instance.clean number
+      
+      # False if it fails the basic check.
+      #
+      return false unless (2..15) === normalized.size
+      
+      # Hint based checking.
+      #
+      cc, ndc, *rest = Phony.split normalized
+      
+      # CC.
+      #
+      cc_needed = hints[:cc]
+      return false if cc_needed && cc_needed != cc
+      
+      # NDC.
+      #
+      ndc_needed = hints[:ndc]
+      return false if ndc_needed && ndc_needed != ndc
+      
+      # Country specific checks.
+      #
+      validator = validator_for cc
+      validator.plausible? ndc, rest
+    rescue StandardError
+      return false
+    end
+    
+    def validator_for cc
+      @validators[cc] || default_validator
+    end
+    
+    def default_validator
+      @default_validator ||= Validator.new
+    end
+    
+  end
+  
+end
\ No newline at end of file
diff --git a/phony.gemspec b/phony.gemspec
index 2904f9a6..2ae5f016 100644
--- a/phony.gemspec
+++ b/phony.gemspec
@@ -1,6 +1,6 @@
 Gem::Specification.new do |s|
   s.name = 'phony'
-  s.version = '1.6.5'
+  s.version = '1.6.6'
   s.authors = ['Florian Hanke']
   s.email = 'florian.hanke+phony@gmail.com'
   s.homepage = 'http://github.com/floere/phony'
diff --git a/spec/lib/phony/validations_spec.rb b/spec/lib/phony/validations_spec.rb
new file mode 100644
index 00000000..bef32761
--- /dev/null
+++ b/spec/lib/phony/validations_spec.rb
@@ -0,0 +1,43 @@
+# encoding: utf-8
+#
+require 'spec_helper'
+
+describe 'validations' do
+
+  describe 'plausible?' do
+
+    it "is correct" do
+      Phony.plausible?('0000000').should be_false
+    end
+    it "is correct" do
+      Phony.plausible?('hello').should be_false
+    end
+    
+    it "is correct" do
+      Phony.plausible?('+41 44 111 22 33').should be_true
+    end
+    it "is correct for explicit checks" do
+      Phony.plausible?('+41 44 111 22 33', cc: '41').should be_true
+    end
+    it "is correct for explicit checks" do
+      Phony.plausible?('+41 44 111 22 33', ndc: '44').should be_true
+    end
+    it "is correct for explicit checks" do
+      Phony.plausible?('+41 44 111 22 33', cc: '1').should be_false
+    end
+    it "is correct for explicit checks" do
+      Phony.plausible?('+41 44 111 22 33', ndc: '43').should be_false
+    end
+    
+    context 'countries' do
+      
+      it "is correct for US numbers" do
+        Phony.plausible?('1-800-692-7753').should be_true
+        Phony.plausible?('1-911').should be_false
+      end
+      
+    end
+    
+  end
+  
+end
\ No newline at end of file
diff --git a/spec/lib/phony_spec.rb b/spec/lib/phony_spec.rb
index 5187236b..5392257a 100644
--- a/spec/lib/phony_spec.rb
+++ b/spec/lib/phony_spec.rb
@@ -57,9 +57,6 @@
       it "should not normalize a number with a correct zero inside" do
         Phony.normalize('+390909709511').should == '390909709511'
       end
-      it "works with completely broken numbers" do
-        Phony.normalize('0000000').should == ''
-      end
     end
   end