Can I bookmark my favourite servers?
Yes and you have two options how to do that.
You can export servers from our web-based server browser: master.bistudio.com/
Just choose the game, filter servers and press "Export to CSV".
Save the file and move it to the folder with the game.
For instance default Steam folder for Arma 2 will be here: C:\Program Files (x86)\Steam\SteamApps\common\Arma 2
Now start the game and you will see the servers in your in-game browser.
Or you can create hosts.txt file in your game folder and manually insert desired servers. For more info about hosts.txt please visit our Wiki here:
https://community.bistudio.com/wiki/hosts.txt
Please note that if you will add large amount of servers for Arma 2 you may experience performance issues in the Arma 2 main menu.