Specification vs result: the specification is the target or limit; the result is what the laboratory measured. mg/mL measures concentration, % w/w measures content by weight, and ppm means parts per million.
“Not detected” and “less than”: ND means the laboratory did not detect the substance within its test capability. A “<” result is below the stated reporting value. Neither means an absolute zero.
Each report applies to its identified sample and tests. Check the batch, date and method. An ingredient certificate describes that ingredient sample; it does not measure every active dose in the finished product.