diff --git a/app/controllers/contestants_controller.rb b/app/controllers/contestants_controller.rb
index 9ff677d..2e763dc 100644
--- a/app/controllers/contestants_controller.rb
+++ b/app/controllers/contestants_controller.rb
@@ -76,6 +76,8 @@ class ContestantsController < ApplicationController
   def convert_csv
     authorize @contest
 
+    @action_name = t("helpers.buttons.back")
+    @action_path = contest_path(@contest)
     @csv_import = CsvImport.find(params[:id])
     @content = JSON.parse(@csv_import.content)
     @form = Forms::CsvConversionForm.new
@@ -92,15 +94,17 @@ class ContestantsController < ApplicationController
       @content.each_with_index do |row, i|
         if all_params["row_#{i}".to_sym] == "1"
           if @form.email_column == -1
-            Contestant.create(name: row[@form.name_column], contest: @contest, time_seconds: 0)
+            Contestant.create(name: row[@form.name_column], contest: @contest)
           else
             logger.info("Email")
-            Contestant.create(name: row[@form.name_column], email: row[@form.email_column], contest: @contest, time_seconds: 0)
+            Contestant.create(name: row[@form.name_column], email: row[@form.email_column], contest: @contest)
           end
         end
       end
       redirect_to contest_path(@contest)
     else
+      @action_name = t("helpers.buttons.back")
+      @action_path = contest_path(@contest)
       render :convert_csv, status: :unprocessable_entity
     end
   end
diff --git a/app/controllers/contests_controller.rb b/app/controllers/contests_controller.rb
index b2f7a1b..6f51a3e 100644
--- a/app/controllers/contests_controller.rb
+++ b/app/controllers/contests_controller.rb
@@ -52,6 +52,8 @@ class ContestsController < ApplicationController
     if @contest.update(contest_params)
       redirect_to @contest
     else
+      @action_name = t("helpers.buttons.back")
+      @action_path = contest_path(@contest)
       render :edit, status: :unprocessable_entity
     end
   end
diff --git a/app/models/contestant.rb b/app/models/contestant.rb
index 140bc99..d682344 100644
--- a/app/models/contestant.rb
+++ b/app/models/contestant.rb
@@ -23,14 +23,16 @@ class Contestant < ApplicationRecord
   belongs_to :contest
   has_many :completions, dependent: :destroy
 
-  before_create :initialize_time_seconds
+  before_validation :initialize_time_seconds_if_empty
 
   validates :name, presence: true
   validates :time_seconds, presence: true
 
   private
 
-  def initialize_time_seconds
-    self.time_seconds = 0
+  def initialize_time_seconds_if_empty
+    if !self.time_seconds
+      self.time_seconds = 0
+    end
   end
 end
diff --git a/app/models/puzzle.rb b/app/models/puzzle.rb
index 5246fe7..2fad557 100644
--- a/app/models/puzzle.rb
+++ b/app/models/puzzle.rb
@@ -24,5 +24,4 @@ class Puzzle < ApplicationRecord
   has_one_attached :image
 
   validates :name, presence: true
-  validates :brand, presence: true
 end
diff --git a/app/views/completions/edit.html.slim b/app/views/completions/edit.html.slim
index db56b82..e132bae 100644
--- a/app/views/completions/edit.html.slim
+++ b/app/views/completions/edit.html.slim
@@ -1 +1 @@
-= render "form", contest: @contest, completion: @completion, submit_text: "Save", method: :patch, url: "/contests/#{@contest.id}/completions/#{@completion.id}"
\ No newline at end of file
+= render "form", contest: @contest, completion: @completion, submit_text: t("helpers.buttons.save"), method: :patch, url: "/contests/#{@contest.id}/completions/#{@completion.id}"
\ No newline at end of file
diff --git a/app/views/completions/new.html.slim b/app/views/completions/new.html.slim
index e51a104..17044f4 100644
--- a/app/views/completions/new.html.slim
+++ b/app/views/completions/new.html.slim
@@ -1 +1 @@
-= render "form", completion: @completion, submit_text: "Create", method: :post, url: "/contests/#{@contest.id}/completions"
\ No newline at end of file
+= render "form", completion: @completion, submit_text: t("helpers.buttons.create"), method: :post, url: "/contests/#{@contest.id}/completions"
\ No newline at end of file
diff --git a/app/views/contestants/_form.html.slim b/app/views/contestants/_form.html.slim
index 93e4524..0ab529b 100644
--- a/app/views/contestants/_form.html.slim
+++ b/app/views/contestants/_form.html.slim
@@ -13,11 +13,12 @@
       .form-floating
         = form.text_field :email, autocomplete: "off", class: "form-control"
         = form.label :email
-    .form-text Optional. Fill this only if you intend to send emails through this app.
+    .form-text
+      = t("activerecord.attributes.contestant.email_description")
   .row.mt-4
     .col
       - if method == :patch
-        = link_to "Delete", contest_contestant_path(contest, contestant), data: { turbo_method: :delete }, class: "btn btn-danger me-2"
+        = link_to t("helpers.buttons.delete"), contest_contestant_path(contest, contestant), data: { turbo_method: :delete }, class: "btn btn-danger me-2"
       = form.submit submit_text, class: "btn btn-primary"
 
 - if method == :patch
@@ -27,27 +28,35 @@
   table.table.table-striped.table-hover
     thead
       tr
+        - if @contest.puzzles.size > 1
+          th scope="col"
+            = t("activerecord.attributes.completion.display_time_from_start")
+          th scope="col"
+            = t("activerecord.attributes.completion.display_relative_time")
+        - else
+          th scope="col"
+            = t("activerecord.attributes.completion.display_time")
         th scope="col"
-          | Time since start
-        th scope="col"
-          | Relative time
-        th scope="col"
-          | Puzzle
+          = t("activerecord.attributes.completion.puzzle")
     tbody
       - @completions.each do |completion|
         tr scope="row"
           td
-            = completion.display_time_from_start 
+            = completion.display_time_from_start
+          - if @contest.puzzles.size > 1
+            td
+              = completion.display_relative_time
           td
-            = completion.display_relative_time
-          td
-            | #{completion.puzzle.name} - #{completion.puzzle.brand}
+            - if !completion.puzzle.brand.blank?
+              | #{completion.puzzle.name} - #{completion.puzzle.brand}
+            - else
+              | #{completion.puzzle.name}
           td
             a.btn.btn-sm.btn-secondary.me-2 href=edit_contest_completion_path(@contest, completion, contestant_id: contestant.id)
-              | Edit
-            = link_to "Delete", contest_completion_path(contest, completion, contestant_id: contestant.id),
+              = t("helpers.buttons.edit")
+            = link_to t("helpers.buttons.delete"), contest_completion_path(contest, completion, contestant_id: contestant.id),
                 data: { turbo_method: :delete }, class: "btn btn-sm btn-secondary"
   .row
     .col
       a.btn.btn-primary href=new_contest_completion_path(@contest, contestant_id: contestant.id)
-        | Add completion
+        = t("helpers.buttons.add")
diff --git a/app/views/contestants/convert_csv.html.slim b/app/views/contestants/convert_csv.html.slim
index e07ab41..a3cce80 100644
--- a/app/views/contestants/convert_csv.html.slim
+++ b/app/views/contestants/convert_csv.html.slim
@@ -26,7 +26,7 @@
             - @content[0].each_with_index do |_, i|
               th scope="col"
                 = t("helpers.field") + "_#{i}"
-            th scope="col"
+            th scope="col" style="white-space: nowrap"
               = t("contestants.import.import_column")
         tbody
           - @content.each_with_index do |row, i|
diff --git a/app/views/contestants/edit.html.slim b/app/views/contestants/edit.html.slim
index fd4680d..e310242 100644
--- a/app/views/contestants/edit.html.slim
+++ b/app/views/contestants/edit.html.slim
@@ -1 +1 @@
-= render "form", contest: @contest, contestant: @contestant, submit_text: "Save", method: :patch, url: "/contests/#{@contest.id}/contestants/#{@contestant.id}"
\ No newline at end of file
+= render "form", contest: @contest, contestant: @contestant, submit_text: t("helpers.buttons.save"), method: :patch, url: "/contests/#{@contest.id}/contestants/#{@contestant.id}"
\ No newline at end of file
diff --git a/app/views/contestants/new.html.slim b/app/views/contestants/new.html.slim
index a9410a2..e644b50 100644
--- a/app/views/contestants/new.html.slim
+++ b/app/views/contestants/new.html.slim
@@ -1 +1 @@
-= render "form", contest: @contest, contestant: @contestant, submit_text: "Add", method: :post, url: "/contests/#{@contest.id}/contestants"
\ No newline at end of file
+= render "form", contest: @contest, contestant: @contestant, submit_text: t("helpers.buttons.add"), method: :post, url: "/contests/#{@contest.id}/contestants"
\ No newline at end of file
diff --git a/app/views/contests/show.html.slim b/app/views/contests/show.html.slim
index 711bf09..e6a74ae 100644
--- a/app/views/contests/show.html.slim
+++ b/app/views/contests/show.html.slim
@@ -103,7 +103,7 @@
       thead
         tr
           th scope="col"
-            | Rank
+            = t("helpers.rank")
           th scope="col"
             = t("activerecord.attributes.contestant.name")
           th scope="col"
diff --git a/config/locales/en.yml b/config/locales/en.yml
index fb4ad11..007b480 100644
--- a/config/locales/en.yml
+++ b/config/locales/en.yml
@@ -38,6 +38,12 @@ en:
               greater_than: "Participant names are required"
   activerecord:
     attributes:
+      completion:
+        contestant: Participant
+        display_time: Time
+        display_time_from_start: Time since start
+        display_relative_time: Time for this puzzle
+        puzzle: Puzzle
       contest:
         name: "Name"
         team: "Team contest"
@@ -45,7 +51,14 @@ en:
         allow_registration: "Allow registration"
         allow_registration_description: "Generates a shareable registration form for this contest"
       contestant:
+        completions: completions
+        display_time: Time
+        email: "Email"
         name: "Name"
+        email_description: "Optional. Used for sending emails through this app, or for identifying participants whose gmeet handle doesn't match their registered name."
+      csv_import:
+        file: File
+        separator: Separator
       message:
         author: "Author"
         processed: "Processed?"
@@ -65,15 +78,28 @@ en:
         completion:
           attributes:
             display_time_from_start:
+              blank: Mandatory
               invalid: "Allowed formats: xx:xx:xx, x:xx:xx, xx:xx, x:xx, xx"
             puzzle_id:
               taken: "This contestant has already completed this puzzle"
+        contest:
+          attributes:
+            name:
+              blank: The contest name cannot be empty
+        contestant:
+          attributes:
+            name:
+              blank: The participant name cannot be empty
         csv_import:
           attributes:
             file:
               blank: "No file selected"
               empty: "This file is empty"
               not_a_csv_file: "it must be a CSV file"
+        puzzle:
+          attributes:
+            name:
+              blank: The puzzle name cannot be empty
   completions:
     edit:
       title: "Edit completion"
@@ -132,9 +158,12 @@ en:
       create: "Create"
       delete: "Delete"
       edit: "Edit"
-      import: "CSV Import"
-      save: "Save"
-    field: "Field"
+      import: CSV Import
+      open: Open
+      save: Save
+    field: Field
+    none: No field selected
+    rank: Rank
   messages:
     convert:
       title: "New completion"
diff --git a/config/locales/fr.yml b/config/locales/fr.yml
index f283d23..452b26b 100644
--- a/config/locales/fr.yml
+++ b/config/locales/fr.yml
@@ -9,6 +9,12 @@ fr:
               greater_than: "Choisir une colonne pour les noms des participant.e.s est nécessaire"
   activerecord:
     attributes:
+      completion:
+        contestant_id: Participant.e
+        display_time: Temps
+        display_time_from_start: Temps depuis le début
+        display_relative_time: Temps pour ce puzzle
+        puzzle: Puzzle
       contest:
         name: "Nom"
         team: "Concours par équipes"
@@ -16,7 +22,14 @@ fr:
         allow_registration: "Autoriser l'inscription via l'interface"
         allow_registration_description: "Génère un formulaire d'inscription pour ce concours"
       contestant:
+        completions: Complétions
+        display_time: Temps
+        email: "Email"
         name: "Nom"
+        email_description: "Optionnel. Utile pour envoyer des emails aux participant.e.s depuis cette app, ou pour reconnaître les pseudos gmeet quand ils ne correspondent pas au nom préalablement entré."
+      csv_import:
+        file: Fichier
+        separator: Délimiteur
       message:
         author: "Auteur.ice"
         processed: "Traité ?"
@@ -36,15 +49,28 @@ fr:
         completion:
           attributes:
             display_time_from_start:
+              blank: Obligatoire
               invalid: "Formats autorisés: xx:xx:xx, x:xx:xx, xx:xx, x:xx, xx"
             puzzle_id:
               taken: "Ce.tte participant.e a déjà complété ce puzzle"
+        contest:
+          attributes:
+            name:
+              blank: Le nom du concours ne peut pas être vide
+        contestant:
+          attributes:
+            name:
+              blank: Le nom du ou de la participant.e ne peut pas être vide
         csv_import:
           attributes:
             file:
               blank: "Aucun fichier sélectionné"
               empty: "Ce fichier est vide"
               not_a_csv_file: "Le fichier doit être au format CSV"
+        puzzle:
+          attributes:
+            name:
+              blank: Le nom du puzzle est obligatoire
   completions:
     edit:
       title: "Modifier la complétion"
@@ -103,9 +129,12 @@ fr:
       create: "Créer"
       delete: "Supprimer"
       edit: "Modifier"
-      import: "Importer un CSV"
-      save: "Modifier"
-    field: "Champ"
+      import: Importer un CSV
+      open: Détails
+      save: Modifier
+    field: Champ
+    none: Aucun champ sélectionné
+    rank: Rang
   messages:
     convert:
       title: "Ajout d'une complétion"