You can post comments for the tasks either from task details page or directly from task list. You will find "Add Comment" menu item in task context menu. Once at least one comment is posted you will see the comments link right after the task description indicating the number of comments for this task.
But that's not everything! With Acunote you can use comments to initiate real discussions because it is possible to notify interested parties (task owner, creator or everybody in the discussion) about new comments by email.

Sometimes when working on the task you would like to share some information (be it
screenshot, patch or anything else) with other members of your team.
Acunote allows you to do that by attaching any file you need to the task.
You will find "Attachments" section on the task details page.