#	Federal Register
1	10/21/2020 - 1926.652(b)(4) - 85:67013-67015 - Excavations (Design of Cave-in Protection Systems); Extension of the Office of Management and Budget's (OMB) Approval of Information Collection (Paperwork) Requirements - PDF

#	Letters of Interpretation
1	05/02/2013 - 1926.652(b)(4) - Regulations governing sloping and benching systems for excavations.
2	07/01/2010 - 1926.652(b)(4) - Can a person who qualifies as a "competent" person under one section of support P also qualify as a competent designer of structural ramps under 1926.651(c)(1)(i)?.
3	12/22/2003 - 1926.652(b)(4) - Registered professional engineer approval requirements for combination trench shield and sloping system trenches with a depth greater than 20 feet.

#	Regulations
1	05/07/2004 - - Requirements for protective systems.