prometheus/docs/disabled_features.md

title	sort_rank
Disabled Features	10

Disabled Features

Here is a list of features that are disabled by default since they are breaking changes or are considered experimental. Their behaviour can change in future releases which will be communicated via the release changelog.

You can enable them using the --enable-feature flag with a comma separated list of features. They may be enabled by default in future versions.

@ Modifier in PromQL

--enable-feature=promql-at-modifier

This feature lets you specify the evaluation time for instant vector selectors, range vector selectors, and subqueries. More details can be found here.