There is a validation of type Item is Numeric on the P1_SALARY item. When the page is submitted, this error message is displayed both as a notification and inline with the item. What will cause the validation error to appear only in the Notification area?

A validation's "Display Location" attribute determines where the error message appears. By default, for item-level validations, the location is "Inline with Field and in Notification". To display the error only in the notification area (at the top of the page), the validation must be disassociated from the specific item. Removing the item from the "Associated Item" attribute effectively converts it to a page-level validation, whose errors, by default, only appear in the notification area.

B. Setting "Value Required" to Yes is a separate item-level property that creates its own validation; it does not alter the display location of other validations.
C. The option "Inline in Notification" is the default and displays the error in both locations. The correct option to show it only in the notification area is "On Error Page". However, removing the associated item achieves the desired outcome described.

Oracle APEX Documentation, 23.2, "Oracle APEX App Builder User's Guide", Section 12.3.1.1 "About the Validation Page". Under the "Error Display" section, it describes how associated items cause inline display. It states, "If an error is not associated with a specific page item, it displays in the page notification area."

Oracle APEX Documentation, 23.2, "Oracle APEX App Builder User's Guide", Section 12.3.1.2 "Editing Validation Attributes". The "Associated Item" attribute is described. By leaving this blank, the validation is no longer tied to a specific field for inline display.