Benefits and Guidelines for using a Prefix or Suffix

It is required to use a prefix or suffix for the name property of the fields in your extension. You would then use the Caption/CaptionML values for what to display to the user.

You must use a prefix/suffix when naming all new objects. When you modify a core Dynamics 365 object using a Table Extension or Page Extension, the prefix must be defined at the control or field level.

Declare your objects with a prefix as shown in the following examples.


table 70000000 MyPrefix Salesperson


page 70000000 MyPrefix Salesperson


codeunit 70000000 MyPrefix Salesperson

Page Extension

        action(MyPrefix Vacation)


There are 2 good reasons to why you may want to proactively use a prefix or suffix

  1. App A and App B both use the same field name (for native Dynamics 365 table) of FAB Salesperson Code. The partner for App B already has the prefix/suffix reserved. A customer wants to install both apps but cannot due to collision of field name. App A will have to reserve a different unique prefix and submit an updated version of their app.

  2. Dynamics 365 developers want to use the name of Salesperson Code. App A (published for months), already has that field name. Microsoft will require the app to prefix its field names by submitting an updated version of their app.

General Rules

  • Tag must be at least 3 characters
  • The object/field name must start or end with the tag
  • If a conflict arises, the one who registered the tag always wins

Examples of Acceptable Prefix/Suffix

No Delimiter

  • FABSalespersonCode
  • SalespersonCodeFAB


  • FAB Salesperson Code
  • Salesperson Code FAB


  • FAB_Salesperson_Code
  • Salesperson_Code_FAB

Contact us at to reserve the prefix/suffix of your choosing