ShowMandatory Property

Sets a value that specifies whether users must enter a value in the selected field or text box. The field is marked on the page with a red asterisk and does not enforce any validation. Once the field is filled, the red asterisk disappears. The ShowMandatory property only controls the UI and overrides any asterisk marking of the NotBlank Property.

The ShowMandatory property can be specified as true, false, or as an expression.

For an example, see the Purchase Invoice page where the Vendor Invoice No field is controlled by the VendorInvoiceNoMandatory expression. VendorInvoiceNoMandatory is a variable that takes the value from the Ext. Doc. No. Mandatory field on the Purchase page and the Payables page.


Using expressions has the limitation that number fields with default values, will be interpreted as having a value, and will not be marked with a red asterisk. For example, on the Customer page, on the Credit Limit (LCY) field, using an expression like Credit Limit (LCY) < 5000 will not result in a red asterisk, even if the value is below 5000, because the field already has a default value.

Also, be aware that while it is possible to use an expression for the ShowMandatory property, the property cannot validate a C/AL function.

Applies to

  • Page fields


The ShowMandatory property controls marking the page field with a red asterisk independently of the NotBlank Property. The ShowMandatory property can be used to mark all page fields, but does not enforce any validation of the field. This means that the user will be able to close a page without entering data.

The NotBlank property can be used to mark the UI on primary key fields with a red asterisk and to enforce a validation error. For more information, see NotBlank Property.

See Also

NotBlank Property