You can add comments to documents.
A comment can contain various markup elements and a description.
When you add comments to part or assembly files, the comments are added to the current state of the model and remember that model state. "State of the model" includes visibility (hidden or shown components, cross sections, transparencies), orientation, zoom level, and pan position.
Comments are displayed on the Markup tab in the SolidWorks eDrawings Manager. When you reply to a comment, the reply is part of a discussion thread.
You can type text in the Description box at the bottom of the Markup tab. This text is added to the active comment and does not appear in the graphics area. Descriptions can contain only text.
To add a comment:
-
Click New Comment
(Markup tab) or .
A new comment 
appears on the Markup 
tab under the Markup Comments 
discussion thread. Comments display the user name and are numbered sequentially.
If no comments are active on the Markup tab, click a markup tool to create a new comment automatically.
- Add markup elements such as text, clouds, and dimensions.
- To add descriptions that do not appear in the graphics area, type text in the Description box at the bottom of the Markup tab. Descriptions can be their own comment, or you can add them to a comment that contains other entities such as text or clouds.