diff --git a/docs/dsl/csv.rst b/docs/dsl/csv.rst
index 8f5ab07..fc9f055 100644
--- a/docs/dsl/csv.rst
+++ b/docs/dsl/csv.rst
@@ -12,6 +12,14 @@ The ``csv`` method is a member of ``Squib::Deck``, but it is also available outs
   Squib::Deck.new(cards: data['name'].size) do
   end
 
+If you have multiple source files which you would like to concatenate use the following::
+
+  cards1 = Squib.csv file: 'cards1.tsv', col_sep: "\t"
+  cards2 = Squib.csv file: 'cards2.tsv', col_sep: "\t"
+
+  all_cards = cards1
+  all_cards['column1'] += cards2['column1']
+  all_cards['column2'] += cards2['column2']
 
 Options
 -------
diff --git a/samples/build_groups/Rakefile b/samples/build_groups/Rakefile
index a3dfad6..886fbf0 100644
--- a/samples/build_groups/Rakefile
+++ b/samples/build_groups/Rakefile
@@ -2,13 +2,13 @@
 require 'squib'
 
 desc 'Build black-and-white by default'
-task default: [:bw]
+task default: [:pnp]
 
 desc 'Build both bw and color'
-task both: [:bw, :color]
+task both: [:pnp, :color]
 
 desc 'Build black-and-white only'
-task :bw do
+task :pnp do
   Squib.enable_build_globally :print_n_play
   load 'build_groups.rb'
 end
@@ -20,7 +20,7 @@ task :color do
 end
 
 desc 'Build a test card'
-task :color do
+task :test do
   Squib.enable_build_globally :test
   load 'build_groups.rb'
 end