About the only forum discussions that I print out are discussions about wildcat cartridges that I deal with, and, more specifically, load data or computer predictions of load data.
I compile the discussion in a smaller, more useful format that eliminates screen names, post counts, avatars, etc, but retains dates. Then I print it and file it with my other hard copies for that particular cartridge. ...With notes, if applicable (known hot; subsonic; poor burn characteristics, etc.).