The feature can be enabled at:
Admin home (Control Panels) > Users & Community > User Settings > User Features > User Favorites

As the feature uses the Wiki Argument Variable {{user}} you should also enable this at:
Admin home (Control Panels) > Editing and Plugins > Wiki Argument Variables

Once both features are enable, you can set the Favorite flag on an object by using in the "Action" menu, " Favorite".

To view your favorites or any other user favorites you can use the PluginList by adding a filter
to display them.

Without the space around {user}

{LIST()}
{filter favorite="{ {user} }"}
{LIST}

Note: The List plugin uses the search index in order to create the favorite list. Therefore, if the index is built while excluding some categories (preference: unified_excluded_categories), items from these categories would not appear on the favorite list even if they are tagged as favorite.

See also: PluginFavorite
Issue Allow viewing user favorites

Or alternative ways to indicate which objects are your favorites, through Ratings and Advanced Ratings

Alias names of this page:
Favourite | Favourites | Favorite