Check 48 Film Project site for file formats and The Rules. The submission window closes on April 30th. Upload online.
Top Winners screen their winning shorts at the Directors Guild of America in Hollywood next year parallel with the Awards Ceremony of the original 48FILM. Category Awards will be made for the Respect Greece entries, and winners will participate in the documentary Respect Greece in key roles. For example, the Best Director will be Assistant Director, the Director of Photography, writer, and editor will participate in this production.
Oh, and one more thing,
Check The Rules before you start.