If you want to enable users to tag other contacts within a story (without tagging them to specific Progress Trackers or tagging them in specific Fields), you can enable the option to tag a contact group’s members in the story.

Watch the walkthrough:

Steps

Go to the Edit Survey Template Editor page (you can get there by either creating a new survey or editing an existing survey)
Make sure that the Tag a Contact Group question appears in the right column (Your Survey Questions)
If the Tag a Contact Group question does not appear in the right column, take a look in the Public Questions Library box on the left side. It will appear there and you can simply click the Add button to make it appear in Your Survey Questions. By default it will be added to the bottom of the list.
Press save
To use this feature while creating a story, you must also create at least one Contact Group. Instructions for how to make use of this feature is in this article: Tag another Contact within an Update