2.5.2 d. of Braille Formats 2011 specifically says, "The meaning or name begins with a capital letter" when explaining how to list the symbols. 2.5.3 a. tells us to list CBC symbols according to the CBC Special Symbols Update. In the update, the symbol descriptions all begin with lower-case letters. Will that be updated at some point? Should we go ahead and capitalize the first letter for our CBC list of symbols?
I have no information about an update regarding this issue, so it is best to treat the current situation as permanent unless and until some kind of update eventually addresses it. In the meantime, I suggest a consistent approach. If you have other special symbols AND CBC symbols, I would capitalize all the special symbols as given in 2.5.2.d. If you have ONLY CBC symbols you can leave them as lower case shown in the special update. However, I do not think it would be incorrect to capitalize them anyway because the general guidelines calls for it. Your choice. Be consistent.