Your invitation letter should list the purpose of the visit, i.e. To attend your Commencement, visit family, etc.What should the letter say? For family, relatives, and friends to visit you temporarily in the US, including coming to Commencement, they will most likely need to apply for a tourist visa. Clearly state the purpose of the applicant's intended visit to the United States, along with the proposed dates of their arrival and departure. Use this template to create your own letter of support for family members as they apply for a visitor visa. Please click the PDF for more instructions. Invitation letters are not requested or used except as evidence that you may have help to illegally overstay your visa. No need to do that at all. All he needs is to seek a visa.