diff --git a/README.md b/README.md
index 9c034f4..3b6293f 100644
--- a/README.md
+++ b/README.md
@@ -46,9 +46,6 @@ See `kitchen_sink.sh` examples.
 
 # Current Status
 
- - [X] Oops, `lipmaa` field needs to be a hash, not an integer!
- - [ ] BUG: Keys that start with a carriage return (`\n`) freeze tokenizer.
- - [ ] Convert literals to constants, remove unused locals, reduce duplication, run linter.
  - [ ] Change message templates to render headers in this order: `author`, `prev`, `lipmaa`, `depth`, `kind`.
  - [ ] Make location of blob folder configurable?
  - [ ] Change `@`, `%`, `&` to `feed.`, `mesg.`, `blob.`, respectively. Better readability, easier onboarding, URL friendly.
diff --git a/lib/pigeon.rb b/lib/pigeon.rb
index 0236a37..55cbda1 100644
--- a/lib/pigeon.rb
+++ b/lib/pigeon.rb
@@ -11,6 +11,7 @@ module Pigeon
   PIGEON_DB_PATH = File.join("pigeon.db")
   DEFAULT_BUNDLE_PATH = File.join(Dir.pwd, "bundle")
   PIGEON_BLOB_PATH = File.join(Dir.home, "pigeon_sha256")
+  MESSAGE_FILE = "messages.pgn"
   # MESSAGE TEMPLATE CONSTANTS:
   HEADER_TPL = "author <%= author %>\nkind <%= kind %>\nprev <%= prev %>\ndepth <%= depth %>\nlipmaa <%= lipmaa %>\n\n"
   BODY_TPL = "<% body.to_a.each do |k, v| %><%= k %>:<%= v %><%= \"\\n\" %><% end %>\n"
@@ -49,6 +50,9 @@ module Pigeon
   NO_DRAFT_FOUND = "NO DRAFT FOUND"
   STRING_KEYS_ONLY = "String keys only"
   MISSING_BODY = "BODY CANT BE EMPTY"
+  STILL_HAVE_DRAFT = "RESET DRAFT (%s) FIRST (db.delete_current_draft)"
+  MISSING_DRAFT = "NO DRAFT. CREATE ONE FIRST. Call db.new_draft(kind, body)"
+  RUNAWAY_LOOP = "RUNAWAY LOOP DETECTED"
 
   # Constants for internal use only:
   FOOTERS_REGEX = Regexp.new("#{SIG_FOOTER}|#{IDENTITY_FOOTER}")
diff --git a/lib/pigeon/database.rb b/lib/pigeon/database.rb
index c071bf9..8fc9dbc 100644
--- a/lib/pigeon/database.rb
+++ b/lib/pigeon/database.rb
@@ -87,8 +87,9 @@ module Pigeon
 
     def new_draft(kind:, body: {})
       old = _get_config(CURRENT_DRAFT)
-      raise "PUBLISH OR RESET CURRENT DRAFT (#{old.kind}) FIRST (call db.delete_current_draft)" if old
-
+      if old
+        raise STILL_HAVE_DRAFT % old.kind
+      end
       _replace_draft(Draft.new(kind: kind, body: body))
     end
 
@@ -100,7 +101,7 @@ module Pigeon
     def get_draft
       draft = store._get_config(CURRENT_DRAFT)
       unless draft
-        raise "THERE IS NO DRAFT. CREATE ONE FIRST. Call db.new_draft(kind, body)"
+        raise MISSING_DRAFT
       end
       draft
     end
@@ -145,11 +146,11 @@ module Pigeon
         .map(&:render)
         .join(BUNDLE_MESSAGE_SEPARATOR)
 
-      File.write(File.join(file_path, "messages.pgn"), content + CR)
+      File.write(File.join(file_path, MESSAGE_FILE), content + CR)
     end
 
     def import_bundle(file_path = DEFAULT_BUNDLE_PATH)
-      bundle = File.read(File.join(file_path, "messages.pgn"))
+      bundle = File.read(File.join(file_path, MESSAGE_FILE))
       tokens = Pigeon::Lexer.tokenize(bundle)
       messages = Pigeon::Parser.parse(self, tokens)
 
diff --git a/lib/pigeon/lexer.rb b/lib/pigeon/lexer.rb
index 7753ff9..37859c1 100644
--- a/lib/pigeon/lexer.rb
+++ b/lib/pigeon/lexer.rb
@@ -47,7 +47,7 @@ module Pigeon
 
     def safety_check
       if @loops > 1000
-        raise "RUNAWAY LOOP DETECTED"
+        raise RUNAWAY_LOOP
       else
         @loops += 1
       end
@@ -86,8 +86,11 @@ module Pigeon
 
     class LexError < StandardError; end
 
+    SYNTAX_ERROR = "Syntax error pos %s by %s field in %s"
+    FOOTER_ERROR = "Parse error at %s. Double carriage return not found."
+
     def flunk!(where)
-      msg = "Syntax error pos #{scanner.pos} by #{@last_good} field in #{where}"
+      msg = SYNTAX_ERROR % [scanner.pos, @last_good, where]
       raise LexError, msg
     end
 
@@ -182,7 +185,7 @@ module Pigeon
         return
       end
 
-      raise LexError, "Parse error at #{scanner.pos}. Double carriage return not found."
+      raise LexError, FOOTER_ERROR % scanner.pos
     end
   end
 end
diff --git a/lib/pigeon/parser.rb b/lib/pigeon/parser.rb
index 51ada7b..285958a 100644
--- a/lib/pigeon/parser.rb
+++ b/lib/pigeon/parser.rb
@@ -2,9 +2,9 @@ module Pigeon
   class Parser
     class DuplicateKeyError < StandardError; end
 
-    def self.parse(db, tokens)
-      raise "NO!" unless db.is_a?(Pigeon::Database)
+    DUPE_KEYS = "Found duplicate keys: %s"
 
+    def self.parse(db, tokens)
       new(db, tokens).parse
     end
 
@@ -49,7 +49,7 @@ module Pigeon
 
     def set(key, value, hash = @scratchpad)
       if hash[key]
-        raise DuplicateKeyError, "Found duplicate keys: #{key}"
+        raise DuplicateKeyError, (DUPE_KEYS % key)
       else
         hash[key] = value
       end
diff --git a/spec/pigeon/bundle_spec.rb b/spec/pigeon/bundle_spec.rb
index 1f1851c..3919276 100644
--- a/spec/pigeon/bundle_spec.rb
+++ b/spec/pigeon/bundle_spec.rb
@@ -29,7 +29,7 @@ RSpec.describe Pigeon::Message do
   it "creates a bundle" do
     expected_bundle = create_fake_messages.map(&:render).join("\n\n") + "\n"
     db.export_bundle
-    actual_bundle = File.read(File.join(Pigeon::DEFAULT_BUNDLE_PATH, "messages.pgn"))
+    actual_bundle = File.read(File.join(Pigeon::DEFAULT_BUNDLE_PATH, Pigeon::MESSAGE_FILE))
     expect(expected_bundle).to eq(actual_bundle)
   end
 
diff --git a/spec/pigeon/lexer_spec.rb b/spec/pigeon/lexer_spec.rb
index c6bdabf..1189e4d 100644
--- a/spec/pigeon/lexer_spec.rb
+++ b/spec/pigeon/lexer_spec.rb
@@ -129,7 +129,7 @@ RSpec.describe Pigeon::Lexer do
   end
 
   it "tokenizes a bundle" do
-    bundle = File.read("./spec/fixtures/normal/messages.pgn")
+    bundle = File.read("./spec/fixtures/normal/#{Pigeon::MESSAGE_FILE}")
     tokens = Pigeon::Lexer.tokenize(bundle)
     EXPECTED_TOKENS1.each_with_index do |_item, i|
       expect(tokens[i]).to eq(EXPECTED_TOKENS1[i])
diff --git a/spec/pigeon/message_spec.rb b/spec/pigeon/message_spec.rb
index bf03cfd..7b1551f 100644
--- a/spec/pigeon/message_spec.rb
+++ b/spec/pigeon/message_spec.rb
@@ -32,8 +32,7 @@ RSpec.describe Pigeon::Message do
 
   it "discards a draft after signing" do
     db.publish_draft(draft)
-    err = "THERE IS NO DRAFT. CREATE ONE FIRST. Call db.new_draft(kind, body)"
-    expect { db.get_draft }.to raise_error(err)
+    expect { db.get_draft }.to raise_error(Pigeon::MISSING_DRAFT)
   end
 
   it "creates a single message" do
diff --git a/spec/pigeon/parser_spec.rb b/spec/pigeon/parser_spec.rb
index db885ae..0474f18 100644
--- a/spec/pigeon/parser_spec.rb
+++ b/spec/pigeon/parser_spec.rb
@@ -6,7 +6,7 @@ RSpec.describe Pigeon::Lexer do
     db.reset_database
     db
   end
-  let(:example_bundle) { File.read("./spec/fixtures/normal/messages.pgn") }
+  let(:example_bundle) { File.read("./spec/fixtures/normal/#{Pigeon::MESSAGE_FILE}") }
   let(:tokens) { Pigeon::Lexer.tokenize(example_bundle) }
 
   BAD_TOKENS = [