I think the distinction being drawn here is between work experience experience requirements for certification certified, and officially issued "paper" requirements (academic degrees, for example) (de oficio)

For example, see this page on certification requirements for becoming a certified occupational safety professional:
http://findarticles.com/p/articles/mi_qa3726/is_199702/ai_n8...

The two types of qualifications required for certification (in addition to the exam) are a combination of documented education and on-the-job experience.

"To attain ASP status, a candidate must demonstrate 48 units of academic credit and pass a seven-hour exam. A baccalaureate degree in safety from a college or university accredited by the Accreditation Board for Engineering and Technology meets the requirement. Engineering degrees are worth 42 units, degrees in physical and natural sciences 30 units, while business administration, industrial education, and psychology degrees are worth 18 units.

To make up for a shortfall, a candidate can apply credits awarded for full-time experience: one credit for each month in a job where safety is the primary function and accounts for 50% or more of the employee's workload.

To take the seven-hour test for the CSP designation a candidate must have 48 units of academic credit and another 48 units (four years) of on-thejob experience. Experience used to meet the academic criteria cannot be used to satisfy the experience requirement."

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Note added at 7 hrs (2008-10-21 02:23:02 GMT)
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I think there's an echo echo in my response!