diff --git a/app/models/metadata_belongs_to.rb b/app/models/metadata_belongs_to.rb
new file mode 100644
index 0000000..89b4676
--- /dev/null
+++ b/app/models/metadata_belongs_to.rb
@@ -0,0 +1,33 @@
+# frozen_string_literal: true
+
+# Almacena el UUID de otro Post
+class MetadataBelongsTo < MetadataRelatedPosts
+  # TODO: Convertir algunos tipos de valores en módulos para poder
+  # implementar varios tipos de campo sin repetir código
+  #
+  # @include MetadataString
+  #
+  # Una string vacía
+  def default_value
+    ''
+  end
+
+  # @see MetadataTemplate
+  def to_param
+    name
+  end
+
+  def validate
+    super
+
+    errors << I18n.t('metadata.belongs_to.missing_post') unless !value.blank? && posts.find(sanitize(value), uuid: true)
+
+    errors.empty?
+  end
+
+  private
+
+  def sanitize(uuid)
+    uuid.gsub(/[^a-f0-9\-]/, '')
+  end
+end
diff --git a/app/models/metadata_template.rb b/app/models/metadata_template.rb
index 27cc3e7..fcca637 100644
--- a/app/models/metadata_template.rb
+++ b/app/models/metadata_template.rb
@@ -39,7 +39,7 @@ MetadataTemplate = Struct.new(:site, :document, :name, :label, :type,
   def validate
     self.errors = []
 
-    errors << I18n.t("metadata.#{type}.cant_be_empty") unless can_be_empty?
+    errors << I18n.t("metadata.cant_be_empty") unless can_be_empty?
 
     errors.empty?
   end
diff --git a/config/locales/en.yml b/config/locales/en.yml
index f8add92..48b7465 100644
--- a/config/locales/en.yml
+++ b/config/locales/en.yml
@@ -31,18 +31,18 @@ en:
     destroyed: 'Removed "%{title}"'
     reorder: 'Reorder'
   metadata:
-    array:
-      cant_be_empty: 'This field cannot be empty'
-    string:
-      cant_be_empty: 'This field cannot be empty'
+    cant_be_empty: 'This field cannot be empty'
     image:
-      cant_be_empty: 'This field cannot be empty'
+      not_an_image: 'Not an image'
+      path_required: 'Missing file for upload'
     event:
       zone_missing: 'Timezone is incorrect'
       date_missing: 'Event date is required'
       date_non_parseable: 'Time is not in the correct format'
       time_non_parseable: 'Date is not in the correct format'
       end_in_the_past: "Event end can't happen before the start"
+    belongs_to:
+      missing_post: "Couldn't find the related post"
   exceptions:
     post:
       site_missing: 'Needs an instance of Site'
diff --git a/config/locales/es.yml b/config/locales/es.yml
index e94d212..58fb3fa 100644
--- a/config/locales/es.yml
+++ b/config/locales/es.yml
@@ -31,12 +31,8 @@ es:
     destroyed: 'Eliminado "%{title}"'
     reorder: 'Reordenados'
   metadata:
-    array:
-      cant_be_empty: 'El campo no puede estar vacío'
-    string:
-      cant_be_empty: 'El campo no puede estar vacío'
+    cant_be_empty: 'El campo no puede estar vacío'
     image:
-      cant_be_empty: 'El campo no puede estar vacío'
       not_an_image: 'No es una imagen'
       path_required: 'Se necesita un archivo de imagen'
     event:
@@ -45,6 +41,8 @@ es:
       date_non_parseable: 'La fecha no está en el formato correcto'
       time_non_parseable: 'La hora no está en el formato correcto'
       end_in_the_past: 'El fin del evento no puede ser anterior al comienzo'
+    belongs_to:
+      missing_post: 'No se pudo encontrar el artículo relacionado'
   exceptions:
     post:
       site_missing: 'Necesita una instancia de Site'