La. Stat. tit. 32 § 1270.24
Suppliers of mechanical repairs and services for any recreational vehicle subject to regulation pursuant to this Chapter shall provide each consumer with an itemized bill indicating repairs and services performed, parts replaced, or materials used, the total labor charge, and the identity of the mechanic, repairman, or supplier who performed the work. However, nothing in this Section shall prohibit a supplier of mechanical repairs and services from charging a service fee for the use of shop supplies such as rags, fender covers, small amounts of fluid, or other items which are not itemized, provided that such fee does not exceed five percent of the total invoice for mechanical repairs or thirty-five dollars, whichever is less.
La. R.S. § 32:1270.24