Braille display equivalent to alt-characters

Hi friends, (first post, woo!) I just got a brailliant 40 and i have it paired with my iphone. I use a lot of accented characters and i know these can be accessed by using the alt key in windows in the option key on macs. For example option a = å option b = ∫ is there anything like an option modifier on my brailliant? is the modifier the same for other braille display devices? ive noticed that pressing dot-8 with my letters renders some accented characters, but theyre not the same ones as my option key on the mac? is there a "universal" equivalent to the option key on every braille display or are the alt characters unique for each one? thank you much, kyle