In my mind, any sort of measurement that involves squaring or cubing in literary text should use the new BF 2011 Nemeth code indicators. Is this a correct interpretation? Things like 10 ft2 (ten square feet) or 1 in3 (one cubic inch).
I'll assume that this is printed with the 2 and 3 numbers as superscript. Then this is considered mathematical notation and is braille in Nemeth with the Nemeth opening and closing indicators. If this is not a Nemeth transcription, then it calls under Section 1.3.3 and 1.3.4, 1.3.5, etc. covering Nemeth notation in nontechnical materials. You'll need the notice of Nemeth code use on the TN page and the special symbols used, since the entire transcription is NOT Nemeth.
The use of Nemeth code provides the precise print usage to the reader and the procedures are clearly given in the Formats guidelines.