...
The Update field will grow as more text is added (sometimes, it takes a space or newline to trigger the resize). The field can also contain simple HTML tags to make the update visually appealing (see Validate Progress Update Tags for more details). Note: a rich text box is not available within the Atlassian UI Kit.
Click Save to create and display the update record within the issue panel.
A notification will be sent to the editor, the assignee, and the watchers of the issue following the notification scheme(s).
...