Since 1953, rulings the IRS deems to be of general interest are officially published as Revenue Rulings (Rev. Rul.). They are less authoritative than regulations but do have precedential value for others in essentially the same circumstances. They are published in the Internal Revenue Bulletin.
Revenue rulings are assigned numbers chronologically by year in this format YY-## (up to 2000) or YYYY-## (2000 and later). For example, Rev. Rul. 90-10 represents the 10th revenue ruling issued in 1990, and Rev. Rul. 2002-5 is the fifth revenue ruling issued in 2002.
Note: Revenue rulings can be revoked or modified. You can check their status using citators such as Shepard’s and Keycite.
Finding Revenue Rulings
Revenue Rulings are available on Westlaw and Lexis Advance from 1953 - present.