diff --git a/db/master-data.cds b/db/master-data.cds
index 950fada3..ae6b9221 100644
--- a/db/master-data.cds
+++ b/db/master-data.cds
@@ -5,9 +5,12 @@ namespace sap.fe.cap.travel;
 @cds.autoexpose @readonly
 aspect MasterData {}
 
+// Annotation @cds.collate: false will disable language-dependent ordering.
+type AirlineId    : String(3) @cds.collate: false;
+type ConnectionId : String(4) @cds.collate: false;
 
 entity Airline : MasterData {
-  key AirlineID : String(3);
+  key AirlineID : AirlineId;
   Name          : String(40);
   CurrencyCode  : Currency;
   AirlinePicURL : String      @UI : {IsImageURL : true};
@@ -15,7 +18,7 @@ entity Airline : MasterData {
 };
 
 entity Airport : MasterData {
-  key AirportID : String(3);
+  key AirportID : String(3) @cds.collate : false;
   Name          : String(40);
   City          : String(40);
   CountryCode   : Country;
@@ -23,7 +26,7 @@ entity Airport : MasterData {
 
 
 entity Supplement : managed, MasterData {
-  key SupplementID : String(10);
+  key SupplementID : String(10) @cds.collate : false;
   Price            : Decimal(16, 3);
   Type             : Association to SupplementType;
   Description      : localized String(1024);
@@ -35,9 +38,9 @@ entity Flight : MasterData {
   // when cuid is added, the to_Airline & to_Connection can be made managed association,
   // furthermore the AirlineID and ConnectionID can be removed,
   // they will be replaced by the generate FKs for to_Airline & to_Connection
-  key AirlineID    : String(3);
+  key AirlineID    : AirlineId;
   key FlightDate   : Date;
-  key ConnectionID : String(4);
+  key ConnectionID : ConnectionId;
 
   Price            : Decimal(16, 3);
   CurrencyCode     : Currency;
@@ -55,8 +58,8 @@ entity FlightConnection : MasterData {
   // once the TODO in Flight is done, similar change can be applied here
   // to_Airline can be managed association and AirlineID can be removed
   // and will be replaced with the generated FK
-  key ConnectionID   : String(4);
-  key AirlineID      : String(3);
+  key ConnectionID   : ConnectionId;
+  key AirlineID      : AirlineId;
   DepartureAirport   : Association to Airport;
   DestinationAirport : Association to Airport;
   DepartureTime      : Time;
@@ -71,7 +74,7 @@ entity FlightConnection : MasterData {
 // showcasing unique constrains ??
 // @assert.unique.email: [EMailAddress]
 entity Passenger : managed, MasterData {
-  key CustomerID : String(6);
+  key CustomerID : String(6)   @cds.collate : false;
   FirstName      : String(40);
   LastName       : String(40);
   Title          : String(10);
@@ -84,7 +87,7 @@ entity Passenger : managed, MasterData {
 };
 
 entity TravelAgency : MasterData {
-  key AgencyID : String(6);
+  key AgencyID : String(6)   @cds.collate : false;
   Name         : String(80);
   Street       : String(60);
   PostalCode   : String(10);
@@ -101,6 +104,7 @@ entity TravelAgency : MasterData {
 //
 
 entity SupplementType : sap.common.CodeList {
+  @cds.collate: false
   key code : String(2) enum {
     Beverage = 'BV';
     Meal     = 'ML';
diff --git a/db/schema.cds b/db/schema.cds
index a53f20b1..e4970ff4 100644
--- a/db/schema.cds
+++ b/db/schema.cds
@@ -4,7 +4,8 @@ using {
   sap.fe.cap.travel.Passenger,
   sap.fe.cap.travel.TravelAgency,
   sap.fe.cap.travel.Supplement,
-  sap.fe.cap.travel.Flight
+  sap.fe.cap.travel.Flight,
+  sap.fe.cap.travel.ConnectionId
  } from './master-data';
 
 namespace sap.fe.cap.travel;
@@ -41,7 +42,7 @@ entity Booking : managed {
   key BookingUUID   : UUID;
   BookingID         : Integer @Core.Computed;
   BookingDate       : Date;
-  ConnectionID      : String(4);
+  ConnectionID      : ConnectionId;
   FlightDate        : Date;
   FlightPrice       : Decimal(16, 3);
   CurrencyCode      : Currency;
@@ -71,6 +72,7 @@ entity BookingSupplement : managed {
 //
 
 entity BookingStatus : CodeList {
+  @cds.collate: false
   key code : String(1) enum {
     New      = 'N';
     Booked   = 'B';
@@ -79,6 +81,7 @@ entity BookingStatus : CodeList {
 };
 
 entity TravelStatus : CodeList {
+  @cds.collate: false
   key code : String(1) enum {
     Open     = 'O';
     Accepted = 'A';