Foxit PDF Editor adds PSI support for free-form annotation. You can use Surface Pro Pen or Wacom Pen to add free-form annotations with PSI in PDFs. Detailed steps are as follows:

• (For Surface Pro users) Choose Comment > Pencil, and then add free-form annotation as needed with Surface Pro Pen;
• (For Wacom tablet users) Connect your Wacom tablet to the computer, choose Comment > Pencil, and then add free-form annotation as needed with Wacom Pen.

1. In the Comment tab, select a type of drawing markup. Then click and drag to make a shape you want to mark up. 
2. (Optional) Sizing handles (small circles or squares) appear at the corners and sides of a selected drawing markup. You can drag these handles to change the size and shape of the markup.
3. (Optional) When you select a drawing markup comment, you will find a toolbar floating around the comment, which allows you to change the color of the comment quickly.

Callout and Textbox are designed for users to create comments in a callout text box or a box.

A callout text box contains a text box and an arrow, which is especially useful when you want to single out (but not obscure) a particular area of a document. 

You can use the Typewriter command to add comments anywhere on a PDF. 

A Typewriter comment 

For how to add a file as a comment and work on it, please refer to File Attachments in Chapter 5. 

Do one of the following:

1. To add a note comment, please click the Note command in the Comment tab, click where you want to place the note. 
2. Add a text message to the Note comment and change the appearance of the Note comment. See also Add a text markup comment.
3. Drag its lower-left or lower-right corner to resize the pop-up note. 
4. Click and drag the title bar of the pop-up note to move its position. 

You can use pin tools to add comments by adding notes and attaching a file. A note comment leaves a note icon on the page where you placed it, and a pop-up note for your text message. Using the File command, you can attach a file in the document as a comment.

Foxit PDF Editor lets you highlight specified areas, such as a certain text range, image, or blank space.

• To highlight an area, select Comment > Area Highlight.
• (Optional) Change the highlight color in the Format tab in the right panel. 
• Click and drag the mouse across the text range, image, or blank space that needs to be highlighted.

Tip: To copy the text in the highlighted area, please do one of the following:

Do one of the following: