I received a mail with a PDF attachment. I need to pass the 20 pages long PDF to a group of people.
This group of people should focus on a part on page 3. I would like to mark this part with a red square, to make it easy for the people to find the important information.
How can I do this?
I use the default Ubuntu LTS (14.04).
Update: I don't want to annotate text like in other questions. I want to draw a colored rectangle.
qpdfview
from the above answers link, for highlighting, and it works very well. – meuh Sep 24 '15 at 16:16