Benefits and Guidelines for using a Prefix or Suffix

In your extension, the name of each new application object or any of its fields must contain a prefix or suffix. This rule applies to all AL objects and fields. You can then use the Caption/CaptionML values for what you decide to display to the user. 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

Page Extension

        action(MyPrefix Vacation)


codeunit 70000000 MyPrefix Salesperson


There are two 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 a 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

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

See Also

Checklist for Submitting Your App
Rules and Guidelines for AL Code