context 4 means Application
The user is using an interactive application that is not a game.
When to send it
Send 4 when the user is engaged with a non-game application such as a utility, a productivity tool, a social or messaging app, or a shopping app. The content is the app's own interface rather than media.
Buyers use 4 for in-app display and native campaigns. It is confused with 2 for casual games and with 5 for news and reading apps, where the user is reading text. Defaulting every app request to 4 makes a reading app look the same as a utility.
Example
{
"app": {
"content": {
"context": 4
}
}
}Fields that carry it
Other values in content contexts
The content contexts list page explains the whole list and its common mistakes.