An LOI, or Letter of Intent, is a written document expressing an actor's intent to be in a specific project, if various conditions are met, without a full contractual commitment or long negotiation.
An LOI should be signed by the actor, or the actor’s representative, within the last calendar year and include the following information:
Name of the project
Name of the producer or production company
Name of the actor
Role the actor is committing to
Other acceptable documents are Deal Memos and Actor Agreements.