feature : Search for the feature you want on https://caniuse.com, then click on the hash sign to the left of the search result heading and you will get the unique name of this feature.
[periods] : Optional parameter. Select the browser versions to display. Supported values: past_1, past_2, past_3, past_4, past_5, current, future_3, future_2, future_1. If this value is empty, the default value current will be used.