The comment block is used to hold text comments that describe the model or a portion of the model. This block is for visual purposes only and has no effect on running the model.
To enter or edit the comment, first click on the icon in the upper left corner in order to activate the comment block. Then click in the editor area to activate the editor.
The comment can contain multiple lines of text, and it can be resized by clicking and dragging any edge or corner while the comment is active for editing.