InfoPath Dev

I want to keep my form simple and set a formatting rule (hide) on a section with 3 fields that should not be visible to the average inputter (everyone) except 2 users. I am working on Sharepoint online

My rule is Hide section

When I am about to create the condition I do not know what to place (I was successful by doubleclicking pc:Person)

Created By

      pc:Person

             DisplayName

             AccountID

             AccountType

 and the subsequent expression

 Person does not contain 'lastname'

However, I am not sure if I need to type name lastname or name.lastname

 I think you need to use DisplayName. Does CreatedBy get populated when the form opens? Or on submit? Maybe drag the display name field onto the form and preview to see. You could also just use the userName function - and compare that to the current user.