In a screenplay, would it be okay to introduce a character through a dialogue? The character in question isn't given a background (in the ACTION) in the start since his first appearance is one where he appears all of a sudden. A couple of lines later, he gets a description of his physical features.
And even though he has a sizeable role (read '3 minutes of screen time') in the film, I have referenced him simply as
MAN in all of the dialogues.
Is it common practice to first have a character speak something and then introduce him to the reader, purely out of narrative demands?
I wish for the answer to hold for the introduction of the protagonist as well. He is introduced with a voice-over and it's only after a minute of VO that you actually get to see him. Should I describe his voice or just get going with it? Also, is it okay to reference him with his own name (in the VO dialogue that he speaks), since he will be introduced later in the very first page?