This is a two step process, one for audio and one for video.While not necessary, it can be helpful to split the sequence on the Avid side into one video only sequence (one video track) and one audio only sequence. (multiple audio tracks if you want).Audio can be exported as a simple OMF type 2 (either embedded or linked to external media is fine).The Video has to be exported as a Quicktime Reference. This is a "linked" export where the actual file produced is very small, like a Pro Tools session doc. In the Quicktime Reference export window, you must uncheck the use Avid codec box. It is the user's responsibility to locate all linked video files for the sequence and send them to the Pro Tools user. For this, it's helpful to "consolidate" the sequence in Express DV before you begin this whole process so that all the files can be dumped to a single location of your choice and the file(s) created will only include the footage plus handles that is being used, potentially saving copy time, disk space, etc.