In regards to using mileage as a business expense the IRS requires a mileage log be kept for:
The amount of mileage
The dates of business trips
The location the taxpayer drove to for business
The business purpose for the trip(s)
Some common errors in mileage logs include:
Not including the business purpose
Using estimates instead of proper documentation
Errors from either negligence or just mistakes
Remember, you don't need to record your odometer reading with each trip but you do need proper documentation.
The documents provided above are not responsible in assisting/preparing a correct tax return. The available forms are only for documenting additional documentation and are not subject to any regulations set forth in Circular 230 of the IRS.