The grading of existing utility information by how it was obtained, from records only (D) to exposed and measured (A), used by PAS 128 in the UK and ASCE 38 in the US.
Utility quality levels grade information about existing underground utilities by how it was obtained: from records only, from site reconnaissance, from detection with geophysical equipment, or by exposing and measuring the utility. The UK's PAS 128 and the US standard ASCE 38 both use levels D, C, B and A, from least to most reliable.
Both standards subdivide some levels (for example by detection accuracy or by method), and define deliverables and reporting. The exact definitions depend on the edition the contract cites.
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