Labels
You can use labels to classify pull requests and to improve your overview over them.
Creating Labels
For organizations, you can define organization-wide labels that are shared with all organization repositories, including both already-existing repositories as well as newly created ones. Organization-wide labels can be created in the organization Settings.
Labels have a mandatory name, a mandatory color, an optional description, and must either be exclusive or not. For more information, see Scoped Labels.
Scoped Labels
Scoped labels are used to ensure at most a single label with the same scope is assigned to pull request. For example, if labels kind/bug and kind/enhancement have the Exclusive option set, a pull request can only be classified as a bug or an enhancement.
A scoped label must contain / in its name (not at either end of the name). The scope of a label is determined based on the last /, so for example the scope of label scope/subscope/item is scope/subscope.
Filtering by Label
Pull request lists can be filtered by label. Selecting multiple labels shows pull requests that have all selected labels assigned.
By holding alt to click the label, pull requests with the chosen label are excluded from the list.