Reply To: acronyms in computer material
If we know that the ARC in question is pronounced separately as letters, then the Rules of UEB 10.12.1 would have us NOT use the "ar" groupsign in that particular ARC "anywhere" it appears, including within a symbols-sequence, like a web address.
The Rules of Unified English Braille, Second Edition 2013 state:
10.12 Miscellaneous
Abbreviations and acronyms
10.12.1 Preferably, when it is known, or can be determined from the text or by reference to a standard dictionary, that letters within an abbreviation or acronym that would make up a contraction are pronounced separately as letters, do not use the contraction. In case of doubt, use the contraction.
Thank you for your question.
NBA's UEB Literary Committee