I am new at IS, anyone knows how to attach multiple model releases to one photo.
I tried  with deep meta and webpage edit, but don't know how.
anyone can help?

It works fine with Deep Meta. You simply have to first click on the "Releases" tab to add your model releases into the Deep Meta program. So in there you should add each model release file for each model you want to attach releases for.

Then, when you are editing the details for a photo you wish to upload, there will be another releases tab that will appear. In there you will see the whole list of model releases you have added previously into Deep Meta. From there you just click as many of the releases that you want to attach to that particular photo.

If you have already uploaded the photo though, and it is still in the inspection cue, then you can add releases through the web site using the method gostwyck mentioned. There is no way to add a model release to an existing upload using Deep Meta once it has been uploaded to iStock.

But if you are planning to add multiple releases though, and the picture is in the inspection cue already, then I would suggest canceling the upload on the iStock web site so that it isn't inspected and then uploading it again through Deep Meta as a new photo with the multiple releases you want to attach.

This will be faster than having to use a photo editing program to create a file with multiple releases inside the file and attach to the upload that is still in the inspection cue.

I hope that helps...