Artglyph provides guidelines for when you need the model and property releases.
The model and property releases grant permission to publish the photo or video in one form or another, commercially or not.
The model and property releases are needed when the subject of the photo or video is an identifiable:
Release Agreements protect you from legal claims by the owner of the property.
When uploading images, photos and footage that depict recognizable persons or identifiable buildings you must acquire a signed release form.
When uploading fonts, audio, 3D models, and parts of other person's work it is incumbent on the uploader to obtain a license.
Whenever required by Artglyph or Purchaser of Final Video you are required to provide a copy of a relevant signed release agreement and license regarding the media included in the uploaded Template as a proof of your rights to the materials.
You can find more information on Release Agreements on Wikipedia