Tank 09 : For purposes of tank entry, cleaning, or repair, a stationary or portable vessel large enough to allow human entry that is intended to contain an accumulation of hazardous substances
NFPA 326 Standard for the Safeguarding of Tanks and Containers for Entry, Cleaning, or Repair, 2005 ed. https://www.nfpa.org/assets/files/AboutTheCodes/32 6/326-F2009-ROC.pdf, (Std: Safeguarding of Tnk and Cont for Entry, Cleaning, or Repr - Amer) {298 NFC}