In order to add a comment to an image select the image and use the Edit->Edit comment command.
Comments are structured in various parts :
1) Comment: a free text describing the picture.
2) Place: the place the picture represents.
3) Date: the date the picture was taken.
4) Keywords: a series of keywords usefull for doing complex search, as described in the section called Find Images in Chapter 7.
Image comments are displayed in the image list as bold text above the filename of the image.
To delete a comment use the command : Edit->Delete comment.