reftype 1 means User Action
The refresh follows something the user did, such as scrolling, swiping or changing a tab.
When to send it
Use 1 when a user action triggers the new ad: scrolling an infinite feed, swiping to the next slide of a gallery, switching tabs in a single-page app. Each RefSettings entry with reftype 1 can carry RefSettings.minint if the slot also enforces a minimum display time.
Buyers tend to see user-triggered refresh as close to a fresh page view, because the user is present and engaged, and they may price it above timed refresh. The value is confused with a true page navigation, which is not a refresh at all, and with 2 (Event) when the content changes without the user doing anything.
Example
{
"imp": [
{
"refresh": {
"refsettings": {
"reftype": 1
}
}
}
]
}Fields that carry it
Other values in auto refresh triggers
The auto refresh triggers list page explains the whole list and its common mistakes.