The deadline to request a Letter of Invitation is November 1st. Complete one form per attendee, and be sure to include all required information.An invitation letter from you. An invitation letter from the National Restaurant Association Show can be a helpful supporting document for your visa application. During registration select the checkbox labeled "I would like a visa invitation letter". Invitation letters will be created for each individual and emailed. The official ALA letter of invitation is to be used to facilitate the processing of any visas or documents needed for you to attend the ALA conference only. Letter of Invitation Application Process. Here are the steps for getting a letter of invitation for an international conference in the USA.