The authoritative instrument for the distribution of all forms of official IRS tax guidance is the Internal Revenue Bulletin (IRB), a weekly collection of these and other items of general interest to the tax professional community.
perfidy definition: The definition of a perfidy is a deliberate betrayal. (noun) An example of a perfidy is spreading a best friend's secrets all over town....
The definition of perilous is a dangerous situation, or something fraught with danger and risk. An example of perilous is when you are barely able to pay your bills and you are about to lose your job.