To be eligible for registration as a professional engineer or land surveyor or for certification as an engineer intern or land surveyor intern, an applicant must be of good character and reputation and shall submit a written application to the board containing such information as the board may require together with five references, three of which references must be professional engineers in the case of engineers or three of which references must be professional land surveyors in the case of land surveyors, having personal knowledge of the applicant’s engineering or land surveying experience, or in the case of an application for certification as an engineer intern or land surveyor intern, by three character references.