Below the Task List is the Note Panel.

If the currently selected task has a note, it is displayed in the Note Panel. You can make changes to the note, or you can write a note for a task that doesn't already have one.
The toolbar at the top of the Note Panel lets you cut or copy text to the clipboard, or paste from the clipboard. You can also use it to make your text bold or italic, or to make numbered or bulleted lists.
If you type in the address of a web page, this is recognized automatically. If you click on it, the web page is opened in your browser.
You can also link to an email address, if you preface it with mailto: - for example, mailto:support@mypocketsoft.com.
You can put the Note Panel on the right hand side of the task list, instead of below it. Select View / Show Notes to Right.