1) The fringe benefit under Davis-Bacon Act, a labor law, includes such as sick leave, vacation, health insurance, etc.
2) Vacation, sick leave, and holiday day pay are compensation. They are included in wages and is subject to payroll taxes including withholding.
3) For a complete list on employee benefits and a broader issue of which ones are subject to taxable wages and/or deductible for the employer, we need to refer to the IRS publication 15-B. https://www.irs.gov/pub/irs-pdf/p15b.pdf
The benefit can include privilege of driving company car and free gym use at the job site.
Please feel free to follow up.
Fiona Chen, MPA, Ph.D., CPA, ABV, CFF, CITP