Optional object fields

Many Web API endpoints return standard objects.
Aside from standard object fields which are always present, you can also see optional fields in object description. Optional fields are returned when they are requested explicitly or included by method defaults.

The benefits are:

• We make API easier to use for developers. They have no need in extra sub-requests, especially in requests returning lists of objects.
• Reduces load on our system when optional fields are not necessary.

In most part of API endpoints optional fields can be included with include_{field_name}=true GET or POST parameter. Some old methods contain separate parameters to include these fields. Such methods docs contain these parameters description.