How to do the invitation letter?

The invitation letter shall be done privately by the inviting individual. There is no such a template for the letter, but the letter should include the followings: information on the applicant (full name, gender, date of birth, etc.); (2) information on the planned visit (arrival and departure dates, place(s) to be visited, etc.); (3) Information on the inviting individual (name, contact telephone number, address, signature of the inviting individual). The invitation letter is not necessarily signed by officials.