Relevant here mostly for what it no longer holds. Miscellaneous itemized deductions have been suspended since 2017, which is why the personal half of a tax preparation fee and a repayment of $3,000 or less are worth nothing rather than worth less.
The official page
Everything here is written from the IRS's own material, and the place to check it is Schedule A on irs.gov. Figures and rules change; the source is what settles them.
This is educational material, not tax advice. Your own situation may turn on facts this page does not know about.