But, there are challenges of finding the law even with complete access to it for a fee, in how it sometimes is assembled. I'll demonstrate this using temporary regulations issued in July 1987 (TD 8145), an IRS notice issued in 1989 that modified parts of the 1987 regulations, a 2020 effort to replace the 1989 notice, and an oddity of a incorrect explanation of part of the 1989 notice in the 2019 IRS Pub 535 on business expenses (it was correct in prior versions of this pub). I'll also attempt to explain why this all happened, AND how it can all be avoided. After all, the tax law is complex enough and should not be made even more complex by challenges of finding that law!