diff --git a/README.md b/README.md
index f2e8878..caa1d4b 100644
--- a/README.md
+++ b/README.md
@@ -33,8 +33,9 @@ gem 'cfonb'
 Below is the list of additional details available for each operation.
 
 These details can be accessed through `operation.details`, which will provide all the attributes. To fetch a specific attribute, you can use `operation.details.attribute`. For example, `operation.details.unstructured_label`. Ultimately, you can also access the 70 characters of the detail by using its code like `operation.details.mmo`
+All unmapped details can be accessed via `details.unknown` which will return the codes and the corresponding line details.
 
-If you encounter new ones, please open an issue or a pull request with the appropriate implementation.
+If you encounter new and relevant ones, please open an issue or a pull request with the appropriate implementation.
 We aimed at making it as easy as possible to add new details. You just need to do the following on initialization:
 
 ```ruby
diff --git a/cfonb.gemspec b/cfonb.gemspec
index 9949e72..6750406 100644
--- a/cfonb.gemspec
+++ b/cfonb.gemspec
@@ -2,7 +2,7 @@
 
 Gem::Specification.new do |s|
   s.name                       = 'cfonb'
-  s.version                    = '1.0.0'
+  s.version                    = '1.1.0'
   s.required_ruby_version      = '>= 3.2'
   s.summary                    = 'CFONB parser'
   s.description                = 'An easy to use CFONB format parser'
diff --git a/lib/cfonb.rb b/lib/cfonb.rb
index ab7e826..91e71f3 100644
--- a/lib/cfonb.rb
+++ b/lib/cfonb.rb
@@ -33,6 +33,7 @@
 require_relative 'cfonb/operation_details/ibe'
 require_relative 'cfonb/operation_details/npo'
 require_relative 'cfonb/operation_details/nbu'
+require_relative 'cfonb/operation_details/unknown'
 
 module CFONB
   def self.parse(input, optimistic: false)
diff --git a/lib/cfonb/operation.rb b/lib/cfonb/operation.rb
index 44180d7..4dc18c7 100644
--- a/lib/cfonb/operation.rb
+++ b/lib/cfonb/operation.rb
@@ -42,8 +42,9 @@ def initialize(line)
 
     def merge_detail(line)
       self.raw += "\n#{line.body}"
+      operation_details = OperationDetails.for(line) || OperationDetails::Unknown
 
-      OperationDetails.for(line)&.apply(details, line)
+      operation_details.apply(details, line)
     end
 
     def type_code
diff --git a/lib/cfonb/operation_details/base.rb b/lib/cfonb/operation_details/base.rb
index dcfc7b9..4e2f45d 100644
--- a/lib/cfonb/operation_details/base.rb
+++ b/lib/cfonb/operation_details/base.rb
@@ -18,6 +18,7 @@ def apply(details, line)
               details.instance_variable_set(:"@#{line.detail_code}", new_instance)
 
               super
+              return if attributes.include?(:unknown)
 
               include_duplicated_code_details(current_details, details)
             end
diff --git a/lib/cfonb/operation_details/unknown.rb b/lib/cfonb/operation_details/unknown.rb
new file mode 100644
index 0000000..32ecbf5
--- /dev/null
+++ b/lib/cfonb/operation_details/unknown.rb
@@ -0,0 +1,20 @@
+# frozen_string_literal: true
+
+module CFONB
+  module OperationDetails
+    class Unknown < Base
+      ATTRIBUTES = %i[unknown].freeze
+
+      def self.apply(details, line)
+        return unless line.respond_to?(:detail)
+
+        details.unknown ||= {}
+        code = line.detail_code
+
+        details.unknown[code] = merge_details(details.unknown[code], line.detail)
+      end
+
+      CFONB::OperationDetails.register('Unknown', self)
+    end
+  end
+end
diff --git a/spec/cfonb/operation_spec.rb b/spec/cfonb/operation_spec.rb
index d31a56f..2aff10a 100644
--- a/spec/cfonb/operation_spec.rb
+++ b/spec/cfonb/operation_spec.rb
@@ -272,6 +272,29 @@
         expect(operation.details.ultimate_creditor).to eq('Patrick')
       end
     end
+
+    context 'with an unknown detail' do
+      let(:detail) do
+        OpenStruct.new(
+          body: '0530004411001871EUR2 0001016255614090823     AAAEUR200000000000740',
+          detail_code: 'AAA',
+          detail: 'EUR200000000000740',
+        )
+      end
+
+      it 'adds the detail to the unknown details hash' do
+        operation.merge_detail(detail)
+
+        expect(operation.details.unknown).to eq({ 'AAA' => 'EUR200000000000740' })
+      end
+
+      it 'updates the current details in case of duplicated codes' do
+        operation.merge_detail(detail)
+        operation.merge_detail(detail)
+
+        expect(operation.details.unknown).to eq({ 'AAA' => "EUR200000000000740\nEUR200000000000740" })
+      end
+    end
   end
 
   describe '#type_code' do
diff --git a/spec/cfonb/parser_spec.rb b/spec/cfonb/parser_spec.rb
index 9925c6b..e9d55c8 100644
--- a/spec/cfonb/parser_spec.rb
+++ b/spec/cfonb/parser_spec.rb
@@ -49,6 +49,11 @@
           exchange_rate: nil,
           purpose: 'PURPOSE',
           debtor: 'INTERNET SFR',
+          unknown: {
+            'AAA' => "INTERNETA AAA\nINTERNETA ABB",
+            'BBB' => 'INTERNETE BBB',
+            'CCC' => 'INTERNETI CCC',
+          },
         )
 
         expect(statements[0].operations[1]).to have_attributes(
diff --git a/spec/files/example.txt b/spec/files/example.txt
index 21e21d3..c8d728e 100644
--- a/spec/files/example.txt
+++ b/spec/files/example.txt
@@ -6,6 +6,10 @@
 0515589916200000EUR2 98765432100B1160519     REFREFERENCE                                                               
 0515589916200000EUR2 98765432100B1160519     RCNOTHER REFERENCE                    PURPOSE                              
 0515589916200000EUR2 98765432100B1160519     NPYINTERNET SFR                                                            
+0515589916200000EUR2 98765432100B1160519     AAAINTERNETA AAA                                                           
+0515589916200000EUR2 98765432100B1160519     AAAINTERNETA ABB                                                           
+0515589916200000EUR2 98765432100B1160519     BBBINTERNETE BBB                                                           
+0515589916200000EUR2 98765432100B1160519     CCCINTERNETI CCC                                                           
 
 0415589916200000EUR2 98765432100B1160519  160519VIR  SEPA DEMONSTRATION          0000000000000000000107}REFERENCE       
 0515589916200000EUR2 98765432100B1160519     NPYELEC ERDF