diff --git a/app/views/custom_fields/_form.html.erb b/app/views/custom_fields/_form.html.erb
index 50075775b..ca8ebaf49 100644
--- a/app/views/custom_fields/_form.html.erb
+++ b/app/views/custom_fields/_form.html.erb
@@ -5,7 +5,12 @@
 <p><%= f.select :field_format, custom_field_formats_for_select(@custom_field), {}, :disabled => !@custom_field.new_record? %></p>
 
 <% if @custom_field.format_in? 'list', 'user', 'version' %>
-<p><%= f.check_box :multiple %></p>
+<p>
+  <%= f.check_box :multiple %>
+  <% if !@custom_field.new_record? && @custom_field.multiple %>
+  <em class="info"><%= l(:text_turning_multiple_off) %></em>
+  <% end %>
+</p>
 <% end %>
 
 <% unless @custom_field.format_in? 'list', 'bool', 'date', 'user', 'version' %>
diff --git a/config/locales/ar.yml b/config/locales/ar.yml
index 9d40813a3..562679e7a 100644
--- a/config/locales/ar.yml
+++ b/config/locales/ar.yml
@@ -1076,3 +1076,5 @@ ar:
   label_in_the_next_days: in the next
   label_in_the_past_days: in the past
   label_attribute_of_user: User's %{name}
+  text_turning_multiple_off: If you disable multiple values, duplicate values will be
+    removed in order to preserve only one value per item.
diff --git a/config/locales/bg.yml b/config/locales/bg.yml
index 2e749f390..13c42be1e 100644
--- a/config/locales/bg.yml
+++ b/config/locales/bg.yml
@@ -1074,3 +1074,5 @@ bg:
   description_date_to: Въведете крайна дата
   text_repository_identifier_info: 'Позволени са малки букви (a-z), цифри, тирета и _.<br />Промяна след създаването му не е възможна.'
   label_attribute_of_user: User's %{name}
+  text_turning_multiple_off: If you disable multiple values, duplicate values will be
+    removed in order to preserve only one value per item.
diff --git a/config/locales/bs.yml b/config/locales/bs.yml
index 987dbbe78..8ab45f58a 100644
--- a/config/locales/bs.yml
+++ b/config/locales/bs.yml
@@ -1089,3 +1089,5 @@ bs:
   label_in_the_next_days: in the next
   label_in_the_past_days: in the past
   label_attribute_of_user: User's %{name}
+  text_turning_multiple_off: If you disable multiple values, duplicate values will be
+    removed in order to preserve only one value per item.
diff --git a/config/locales/ca.yml b/config/locales/ca.yml
index 9b31d2e19..a332e94d7 100644
--- a/config/locales/ca.yml
+++ b/config/locales/ca.yml
@@ -1078,3 +1078,5 @@ ca:
   label_in_the_next_days: in the next
   label_in_the_past_days: in the past
   label_attribute_of_user: User's %{name}
+  text_turning_multiple_off: If you disable multiple values, duplicate values will be
+    removed in order to preserve only one value per item.
diff --git a/config/locales/cs.yml b/config/locales/cs.yml
index b882a0988..1f965ab70 100644
--- a/config/locales/cs.yml
+++ b/config/locales/cs.yml
@@ -1079,3 +1079,5 @@ cs:
   label_in_the_next_days: in the next
   label_in_the_past_days: in the past
   label_attribute_of_user: User's %{name}
+  text_turning_multiple_off: If you disable multiple values, duplicate values will be
+    removed in order to preserve only one value per item.
diff --git a/config/locales/da.yml b/config/locales/da.yml
index 9de271a31..e08b94ece 100644
--- a/config/locales/da.yml
+++ b/config/locales/da.yml
@@ -1093,3 +1093,5 @@ da:
   label_in_the_next_days: in the next
   label_in_the_past_days: in the past
   label_attribute_of_user: User's %{name}
+  text_turning_multiple_off: If you disable multiple values, duplicate values will be
+    removed in order to preserve only one value per item.
diff --git a/config/locales/de.yml b/config/locales/de.yml
index 673a4459b..4f5da787a 100644
--- a/config/locales/de.yml
+++ b/config/locales/de.yml
@@ -1088,3 +1088,5 @@ de:
   version_status_open: offen
   
   warning_attachments_not_saved: "%{count} Datei(en) konnten nicht gespeichert werden."
+  text_turning_multiple_off: If you disable multiple values, duplicate values will be
+    removed in order to preserve only one value per item.
diff --git a/config/locales/el.yml b/config/locales/el.yml
index 169214962..1dc201afc 100644
--- a/config/locales/el.yml
+++ b/config/locales/el.yml
@@ -1076,3 +1076,5 @@ el:
   label_in_the_next_days: in the next
   label_in_the_past_days: in the past
   label_attribute_of_user: User's %{name}
+  text_turning_multiple_off: If you disable multiple values, duplicate values will be
+    removed in order to preserve only one value per item.
diff --git a/config/locales/en-GB.yml b/config/locales/en-GB.yml
index 3918f3b94..14bd64aae 100644
--- a/config/locales/en-GB.yml
+++ b/config/locales/en-GB.yml
@@ -1078,3 +1078,5 @@ en-GB:
   label_in_the_next_days: in the next
   label_in_the_past_days: in the past
   label_attribute_of_user: User's %{name}
+  text_turning_multiple_off: If you disable multiple values, duplicate values will be
+    removed in order to preserve only one value per item.
diff --git a/config/locales/en.yml b/config/locales/en.yml
index c3551af17..c63b3bc3a 100644
--- a/config/locales/en.yml
+++ b/config/locales/en.yml
@@ -1026,6 +1026,7 @@ en:
   text_account_destroy_confirmation: "Are you sure you want to proceed?\nYour account will be permanently deleted, with no way to reactivate it."
   text_session_expiration_settings: "Warning: changing these settings may expire the current sessions including yours."
   text_project_closed: This project is closed and read-only.
+  text_turning_multiple_off: "If you disable multiple values, duplicate values will be removed in order to preserve only one value per item."
 
   default_role_manager: Manager
   default_role_developer: Developer
diff --git a/config/locales/es.yml b/config/locales/es.yml
index 84fdbbc90..46c183b8d 100644
--- a/config/locales/es.yml
+++ b/config/locales/es.yml
@@ -1113,3 +1113,5 @@ es:
   label_in_the_next_days: in the next
   label_in_the_past_days: in the past
   label_attribute_of_user: User's %{name}
+  text_turning_multiple_off: If you disable multiple values, duplicate values will be
+    removed in order to preserve only one value per item.
diff --git a/config/locales/et.yml b/config/locales/et.yml
index 8c9c3d940..2b4530699 100644
--- a/config/locales/et.yml
+++ b/config/locales/et.yml
@@ -1089,3 +1089,5 @@ et:
   label_in_the_next_days: in the next
   label_in_the_past_days: in the past
   label_attribute_of_user: User's %{name}
+  text_turning_multiple_off: If you disable multiple values, duplicate values will be
+    removed in order to preserve only one value per item.
diff --git a/config/locales/eu.yml b/config/locales/eu.yml
index 066a44e35..cf1cbe71e 100644
--- a/config/locales/eu.yml
+++ b/config/locales/eu.yml
@@ -1077,3 +1077,5 @@ eu:
   label_in_the_next_days: in the next
   label_in_the_past_days: in the past
   label_attribute_of_user: User's %{name}
+  text_turning_multiple_off: If you disable multiple values, duplicate values will be
+    removed in order to preserve only one value per item.
diff --git a/config/locales/fa.yml b/config/locales/fa.yml
index 55bc59a02..a829b3c99 100644
--- a/config/locales/fa.yml
+++ b/config/locales/fa.yml
@@ -1078,3 +1078,5 @@ fa:
   label_in_the_next_days: in the next
   label_in_the_past_days: in the past
   label_attribute_of_user: User's %{name}
+  text_turning_multiple_off: If you disable multiple values, duplicate values will be
+    removed in order to preserve only one value per item.
diff --git a/config/locales/fi.yml b/config/locales/fi.yml
index e00691995..9be7a6989 100644
--- a/config/locales/fi.yml
+++ b/config/locales/fi.yml
@@ -1097,3 +1097,5 @@ fi:
   label_in_the_next_days: in the next
   label_in_the_past_days: in the past
   label_attribute_of_user: User's %{name}
+  text_turning_multiple_off: If you disable multiple values, duplicate values will be
+    removed in order to preserve only one value per item.
diff --git a/config/locales/fr.yml b/config/locales/fr.yml
index 60ccd50a2..8229a43ad 100644
--- a/config/locales/fr.yml
+++ b/config/locales/fr.yml
@@ -984,6 +984,7 @@ fr:
   text_account_destroy_confirmation: "Êtes-vous sûr de vouloir continuer ?\nVotre compte sera définitivement supprimé, sans aucune possibilité de le réactiver."
   text_session_expiration_settings: "Attention : le changement de ces paramètres peut entrainer l'expiration des sessions utilisateurs en cours, y compris la vôtre."
   text_project_closed: Ce projet est fermé et accessible en lecture seule.
+  text_turning_multiple_off: "Si vous désactivez les valeurs multiples, les valeurs en double seront supprimées pour n'en conserver qu'une par objet."
 
   default_role_manager: "Manager "
   default_role_developer: "Développeur "
diff --git a/config/locales/gl.yml b/config/locales/gl.yml
index 8ec8c99af..b5801104f 100644
--- a/config/locales/gl.yml
+++ b/config/locales/gl.yml
@@ -1087,3 +1087,5 @@ gl:
   label_in_the_next_days: in the next
   label_in_the_past_days: in the past
   label_attribute_of_user: User's %{name}
+  text_turning_multiple_off: If you disable multiple values, duplicate values will be
+    removed in order to preserve only one value per item.
diff --git a/config/locales/he.yml b/config/locales/he.yml
index 4a58cca24..86d1732cc 100644
--- a/config/locales/he.yml
+++ b/config/locales/he.yml
@@ -1081,3 +1081,5 @@ he:
   label_in_the_next_days: in the next
   label_in_the_past_days: in the past
   label_attribute_of_user: User's %{name}
+  text_turning_multiple_off: If you disable multiple values, duplicate values will be
+    removed in order to preserve only one value per item.
diff --git a/config/locales/hr.yml b/config/locales/hr.yml
index 0fa9743cd..d9623ff92 100644
--- a/config/locales/hr.yml
+++ b/config/locales/hr.yml
@@ -1077,3 +1077,5 @@ hr:
   label_in_the_next_days: in the next
   label_in_the_past_days: in the past
   label_attribute_of_user: User's %{name}
+  text_turning_multiple_off: If you disable multiple values, duplicate values will be
+    removed in order to preserve only one value per item.
diff --git a/config/locales/hu.yml b/config/locales/hu.yml
index 1531cc732..c44414462 100644
--- a/config/locales/hu.yml
+++ b/config/locales/hu.yml
@@ -1095,3 +1095,5 @@
   label_in_the_next_days: in the next
   label_in_the_past_days: in the past
   label_attribute_of_user: User's %{name}
+  text_turning_multiple_off: If you disable multiple values, duplicate values will be
+    removed in order to preserve only one value per item.
diff --git a/config/locales/id.yml b/config/locales/id.yml
index 3f1b8b1a3..7459fd6db 100644
--- a/config/locales/id.yml
+++ b/config/locales/id.yml
@@ -1080,3 +1080,5 @@ id:
   label_in_the_next_days: in the next
   label_in_the_past_days: in the past
   label_attribute_of_user: User's %{name}
+  text_turning_multiple_off: If you disable multiple values, duplicate values will be
+    removed in order to preserve only one value per item.
diff --git a/config/locales/it.yml b/config/locales/it.yml
index a43310e1e..12147d992 100644
--- a/config/locales/it.yml
+++ b/config/locales/it.yml
@@ -1077,3 +1077,5 @@ it:
   label_in_the_next_days: in the next
   label_in_the_past_days: in the past
   label_attribute_of_user: User's %{name}
+  text_turning_multiple_off: If you disable multiple values, duplicate values will be
+    removed in order to preserve only one value per item.
diff --git a/config/locales/ja.yml b/config/locales/ja.yml
index 0e33ab43d..a0ab793fd 100644
--- a/config/locales/ja.yml
+++ b/config/locales/ja.yml
@@ -1106,3 +1106,5 @@ ja:
   label_in_the_next_days: 今後○日
   label_in_the_past_days: 過去○日
   label_attribute_of_user: ユーザーの %{name}
+  text_turning_multiple_off: If you disable multiple values, duplicate values will be
+    removed in order to preserve only one value per item.
diff --git a/config/locales/ko.yml b/config/locales/ko.yml
index a10c6774a..36d0c632f 100644
--- a/config/locales/ko.yml
+++ b/config/locales/ko.yml
@@ -1126,3 +1126,5 @@ ko:
   label_in_the_next_days: 다음
   label_in_the_past_days: 지난
   label_attribute_of_user: User's %{name}
+  text_turning_multiple_off: If you disable multiple values, duplicate values will be
+    removed in order to preserve only one value per item.
diff --git a/config/locales/lt.yml b/config/locales/lt.yml
index 1042b36a1..d745ef08e 100644
--- a/config/locales/lt.yml
+++ b/config/locales/lt.yml
@@ -1135,3 +1135,5 @@ lt:
   label_in_the_next_days: per ateinančias
   label_in_the_past_days: per paskutines
   label_attribute_of_user: User's %{name}
+  text_turning_multiple_off: If you disable multiple values, duplicate values will be
+    removed in order to preserve only one value per item.
diff --git a/config/locales/lv.yml b/config/locales/lv.yml
index a864dfdbf..f89325dab 100644
--- a/config/locales/lv.yml
+++ b/config/locales/lv.yml
@@ -1070,3 +1070,5 @@ lv:
   label_in_the_next_days: in the next
   label_in_the_past_days: in the past
   label_attribute_of_user: User's %{name}
+  text_turning_multiple_off: If you disable multiple values, duplicate values will be
+    removed in order to preserve only one value per item.
diff --git a/config/locales/mk.yml b/config/locales/mk.yml
index b162c8345..1dcdceea9 100644
--- a/config/locales/mk.yml
+++ b/config/locales/mk.yml
@@ -1076,3 +1076,5 @@ mk:
   label_in_the_next_days: in the next
   label_in_the_past_days: in the past
   label_attribute_of_user: User's %{name}
+  text_turning_multiple_off: If you disable multiple values, duplicate values will be
+    removed in order to preserve only one value per item.
diff --git a/config/locales/mn.yml b/config/locales/mn.yml
index 0e9b937a9..4e7ae4eff 100644
--- a/config/locales/mn.yml
+++ b/config/locales/mn.yml
@@ -1077,3 +1077,5 @@ mn:
   label_in_the_next_days: in the next
   label_in_the_past_days: in the past
   label_attribute_of_user: User's %{name}
+  text_turning_multiple_off: If you disable multiple values, duplicate values will be
+    removed in order to preserve only one value per item.
diff --git a/config/locales/nl.yml b/config/locales/nl.yml
index 259953f44..fe1c709df 100644
--- a/config/locales/nl.yml
+++ b/config/locales/nl.yml
@@ -1058,3 +1058,5 @@ nl:
   label_in_the_next_days: in the next
   label_in_the_past_days: in the past
   label_attribute_of_user: User's %{name}
+  text_turning_multiple_off: If you disable multiple values, duplicate values will be
+    removed in order to preserve only one value per item.
diff --git a/config/locales/no.yml b/config/locales/no.yml
index b239d161b..524008443 100644
--- a/config/locales/no.yml
+++ b/config/locales/no.yml
@@ -1066,3 +1066,5 @@
   label_in_the_next_days: in the next
   label_in_the_past_days: in the past
   label_attribute_of_user: User's %{name}
+  text_turning_multiple_off: If you disable multiple values, duplicate values will be
+    removed in order to preserve only one value per item.
diff --git a/config/locales/pl.yml b/config/locales/pl.yml
index ccbd689ae..30f766216 100644
--- a/config/locales/pl.yml
+++ b/config/locales/pl.yml
@@ -1088,3 +1088,5 @@ pl:
   label_in_the_next_days: in the next
   label_in_the_past_days: in the past
   label_attribute_of_user: User's %{name}
+  text_turning_multiple_off: If you disable multiple values, duplicate values will be
+    removed in order to preserve only one value per item.
diff --git a/config/locales/pt-BR.yml b/config/locales/pt-BR.yml
index 3658c818a..05d80b221 100644
--- a/config/locales/pt-BR.yml
+++ b/config/locales/pt-BR.yml
@@ -1097,3 +1097,5 @@ pt-BR:
   label_in_the_next_days: in the next
   label_in_the_past_days: in the past
   label_attribute_of_user: User's %{name}
+  text_turning_multiple_off: If you disable multiple values, duplicate values will be
+    removed in order to preserve only one value per item.
diff --git a/config/locales/pt.yml b/config/locales/pt.yml
index 06d79a82b..ba1c59b56 100644
--- a/config/locales/pt.yml
+++ b/config/locales/pt.yml
@@ -1081,3 +1081,5 @@ pt:
   label_in_the_next_days: in the next
   label_in_the_past_days: in the past
   label_attribute_of_user: User's %{name}
+  text_turning_multiple_off: If you disable multiple values, duplicate values will be
+    removed in order to preserve only one value per item.
diff --git a/config/locales/ro.yml b/config/locales/ro.yml
index 8791313b8..f7476a48b 100644
--- a/config/locales/ro.yml
+++ b/config/locales/ro.yml
@@ -1071,3 +1071,5 @@ ro:
   label_in_the_next_days: in the next
   label_in_the_past_days: in the past
   label_attribute_of_user: User's %{name}
+  text_turning_multiple_off: If you disable multiple values, duplicate values will be
+    removed in order to preserve only one value per item.
diff --git a/config/locales/ru.yml b/config/locales/ru.yml
index f3b339525..00120b781 100644
--- a/config/locales/ru.yml
+++ b/config/locales/ru.yml
@@ -1184,3 +1184,5 @@ ru:
   label_in_the_next_days: в средующие дни
   label_in_the_past_days: в прошлые дни
   label_attribute_of_user: Пользователь %{name}
+  text_turning_multiple_off: If you disable multiple values, duplicate values will be
+    removed in order to preserve only one value per item.
diff --git a/config/locales/sk.yml b/config/locales/sk.yml
index dcfff9301..4193a82e4 100644
--- a/config/locales/sk.yml
+++ b/config/locales/sk.yml
@@ -1073,3 +1073,5 @@ sk:
   label_in_the_next_days: in the next
   label_in_the_past_days: in the past
   label_attribute_of_user: User's %{name}
+  text_turning_multiple_off: If you disable multiple values, duplicate values will be
+    removed in order to preserve only one value per item.
diff --git a/config/locales/sl.yml b/config/locales/sl.yml
index 72ec96c22..522cb5d50 100644
--- a/config/locales/sl.yml
+++ b/config/locales/sl.yml
@@ -1076,3 +1076,5 @@ sl:
   label_in_the_next_days: in the next
   label_in_the_past_days: in the past
   label_attribute_of_user: User's %{name}
+  text_turning_multiple_off: If you disable multiple values, duplicate values will be
+    removed in order to preserve only one value per item.
diff --git a/config/locales/sq.yml b/config/locales/sq.yml
index ffe46e273..70c74b3dd 100644
--- a/config/locales/sq.yml
+++ b/config/locales/sq.yml
@@ -1072,3 +1072,5 @@ sq:
   label_in_the_next_days: in the next
   label_in_the_past_days: in the past
   label_attribute_of_user: User's %{name}
+  text_turning_multiple_off: If you disable multiple values, duplicate values will be
+    removed in order to preserve only one value per item.
diff --git a/config/locales/sr-YU.yml b/config/locales/sr-YU.yml
index 9e8cdced0..56850e4dc 100644
--- a/config/locales/sr-YU.yml
+++ b/config/locales/sr-YU.yml
@@ -1078,3 +1078,5 @@ sr-YU:
   label_in_the_next_days: in the next
   label_in_the_past_days: in the past
   label_attribute_of_user: User's %{name}
+  text_turning_multiple_off: If you disable multiple values, duplicate values will be
+    removed in order to preserve only one value per item.
diff --git a/config/locales/sr.yml b/config/locales/sr.yml
index cea002423..c34c0ea95 100644
--- a/config/locales/sr.yml
+++ b/config/locales/sr.yml
@@ -1077,3 +1077,5 @@ sr:
   label_in_the_next_days: in the next
   label_in_the_past_days: in the past
   label_attribute_of_user: User's %{name}
+  text_turning_multiple_off: If you disable multiple values, duplicate values will be
+    removed in order to preserve only one value per item.
diff --git a/config/locales/sv.yml b/config/locales/sv.yml
index 5b4edd810..54e400196 100644
--- a/config/locales/sv.yml
+++ b/config/locales/sv.yml
@@ -1115,3 +1115,5 @@ sv:
   description_date_from: Ange startdatum
   description_date_to: Ange slutdatum
   text_repository_identifier_info: 'Endast gemener (a-z), siffror, streck och understreck är tillåtna.<br />När identifieraren sparats kan den inte ändras.'
+  text_turning_multiple_off: If you disable multiple values, duplicate values will be
+    removed in order to preserve only one value per item.
diff --git a/config/locales/th.yml b/config/locales/th.yml
index 1419de989..c8cb5a5dc 100644
--- a/config/locales/th.yml
+++ b/config/locales/th.yml
@@ -1073,3 +1073,5 @@ th:
   label_in_the_next_days: in the next
   label_in_the_past_days: in the past
   label_attribute_of_user: User's %{name}
+  text_turning_multiple_off: If you disable multiple values, duplicate values will be
+    removed in order to preserve only one value per item.
diff --git a/config/locales/tr.yml b/config/locales/tr.yml
index 099dfe36e..35a8f2bdf 100644
--- a/config/locales/tr.yml
+++ b/config/locales/tr.yml
@@ -1095,3 +1095,5 @@ tr:
   label_in_the_next_days: in the next
   label_in_the_past_days: in the past
   label_attribute_of_user: User's %{name}
+  text_turning_multiple_off: If you disable multiple values, duplicate values will be
+    removed in order to preserve only one value per item.
diff --git a/config/locales/uk.yml b/config/locales/uk.yml
index e4ae488fa..54ec0a05e 100644
--- a/config/locales/uk.yml
+++ b/config/locales/uk.yml
@@ -1071,3 +1071,5 @@ uk:
   label_in_the_next_days: in the next
   label_in_the_past_days: in the past
   label_attribute_of_user: User's %{name}
+  text_turning_multiple_off: If you disable multiple values, duplicate values will be
+    removed in order to preserve only one value per item.
diff --git a/config/locales/vi.yml b/config/locales/vi.yml
index 80e857da8..3f00db7b8 100644
--- a/config/locales/vi.yml
+++ b/config/locales/vi.yml
@@ -1127,3 +1127,5 @@ vi:
   label_in_the_next_days: in the next
   label_in_the_past_days: in the past
   label_attribute_of_user: User's %{name}
+  text_turning_multiple_off: If you disable multiple values, duplicate values will be
+    removed in order to preserve only one value per item.
diff --git a/config/locales/zh-TW.yml b/config/locales/zh-TW.yml
index 11359b9a0..edda122a2 100644
--- a/config/locales/zh-TW.yml
+++ b/config/locales/zh-TW.yml
@@ -1157,3 +1157,5 @@
   description_date_to: 輸入結束日期
   text_repository_identifier_info: '僅允許使用小寫英文字母 (a-z), 阿拉伯數字, 虛線與底線。<br />一旦儲存之後, 代碼便無法再次被更改。'
   label_attribute_of_user: User's %{name}
+  text_turning_multiple_off: If you disable multiple values, duplicate values will be
+    removed in order to preserve only one value per item.
diff --git a/config/locales/zh.yml b/config/locales/zh.yml
index 7f8fb72ff..fd78afef5 100644
--- a/config/locales/zh.yml
+++ b/config/locales/zh.yml
@@ -1080,3 +1080,5 @@ zh:
   label_in_the_next_days: in the next
   label_in_the_past_days: in the past
   label_attribute_of_user: User's %{name}
+  text_turning_multiple_off: If you disable multiple values, duplicate values will be
+    removed in order to preserve only one value per item.