How to copy the task ID and summary

The task ID is a randomly generated four-digit unique identifier for a task. You can view this identifier at the right of your tasks in you list view, by selecting that option in the "columns" preferences as It is shown below:

You can use the task ID to discuss the task with your team members. Clicking on the task ID in the web app will allow you to copy it. Clicking on it twice will allow you to copy the task ID as well as the task summary (title) to your clipboard.

Learn how to copy the URL/task link here.