Related Clues:

• Create software
• Building inspector's reference
• It may involve an exchange of letters
• Make it necessary to decrypt
• English following fake set of rules
• System of standards
• Area ___ (part of a phone number)
• Word with ''bar'' or ''area''
• Word after ''area'' or ''dress''
• Area ___ (phone number part)
• Telephone area ___
• Zip ___
• Cryptographers break it
• Do some cryptography
• Pearl Jam's 4th "No ___"