Question: What must a doctor have to be licensed or registered?
About the article "Medicine", section "Legal controls".

Candidate passages:
The GMC is now empowered to license and regularly revalidate the practice of doctors in the UK.
When the licensing scheme was introduced in 2009, 13,500 (6.1%) of registered doctors chose not to be licensed.
Unlicensed but registered doctors are likely to be non-practising lecturers, managers, or practising overseas, or retired.
Whereas all registered doctors in the UK were offered a one-off automatic practise license in November 2009, since December 2012 no license will be automatically revalidated, but will be subject to a revalidation process every five years.
No doctor may now be registered for the first time without also being issued a license to practice, although a licensed doctor may give up their licence if they choose.
No unlicensed but registered doctor in the UK is subject to revalidation.
However, unlicensed but registered doctors in the UK are still subject to fitness-to-practice proceedings, and required to follow the GMC's good medical practice guidance. 
Pharmacists must be licensed by the state pharmacy board of the state in which they wish to practice, with one exception: A pharmacist with an active license may practice in a federal facility regardless of the state which issued the license.
In order to obtain an initial license, or license by examination, a candidate must have graduated from an AACP accredited school or college of pharmacy, satisfy requirements for internship, write and pass the North American Pharmacist Licensure Examination (NAPLEX), in some states write and pass the Multi-state Pharmacy Jurisprudence Exam (MPJE) and sometimes an additional state exam.
Upon licensure, one may then be designated "Pharmacist" or "Registered Pharmacist" ("R. Ph.
"), as usage of these titles are generally regulated by state governments.
According to the ACPE, accreditation can be granted for the baccalaureate in pharmacy degree and the doctor of pharmacy degree.
The doctor of pharmacy degree is designed to produce graduates who are “educationally prepared for practice and should satisfy educational requirements for licensure.” Students who receive a baccalaureate degree in pharmacy or pharmaceutical sciences are not eligible for licensure as a pharmacist.
After obtaining a license, it must be periodically renewed by completing continuing education and other requirements as prescribed by the state of licensure. 
Regulation and licensure in engineering is established by various jurisdictions of the world to encourage public welfare, safety, well-being and other interests of the general public, and to define the licensure process through which an engineer becomes authorized to practice engineering and/or provide engineering professional services to the public.
As with many other professions, the professional status and the actual practice of professional engineering is legally defined and protected by law.
In some jurisdictions, only licensed engineers (sometimes called registered engineers) are permitted to "practice engineering," which requires careful definition in order to resolve potential overlap or ambiguity with respect to certain other professions which may or may not be themselves regulated (e.g.
"scientists," or "architects").
Relatedly, jurisdictions that license according to particular engineering discipline need to define those boundaries carefully as well so that practitioners understand what they are permitted to do.
In many cases, only a licensed/registered engineer has the authority to take legal responsibility for engineering work or projects (typically via a seal or stamp on the relevant design documentation).
Regulations may require that only a licensed or registered engineer can sign, seal, or stamp technical documentation such as reports, plats, engineering drawings and calculations for study estimate or valuation, or carry out design, analysis, repair, servicing, maintenance or supervision of engineering work, process or project.
In cases where public safety, property or welfare is concerned, it is most likely required that an engineer be licensed or registered — though some jurisdictions have an "industrial exemption" that permits engineers to work internally for an organization without licensure so long as they are not making final decisions to release product to the public or offering engineering services directly to the public (e.g.
Expert witness or opinion in courts or before government committees or commissions can only be given by a registered or licensed engineer.
Engineering colleges generally prefer their faculty or professors to be licensed engineers. 
The U.S Department of Agriculture (USDA) requires businesses that either buy or sell warmblooded animals, exhibit them to the public, transport them commercially, or use them in teaching or experiments, must be licensed or registered.
Failure to become licensed or registered is a punishable violation of the Animal Welfare Act.
Depending on the basis of the business, the Animal and Plant Health Inspection services (APHIS) determines whether the business should be licensed, registered, or both.
Business owners are responsible for knowing about registration and licensing requirements.  
In Canada, a stockbroker is called a "Registered Representative" or an "Investment Advisor".
To be licensed as a Registered Representative and thus qualified to offer investment advice and trade all instruments with the exception of derivatives, an individual employed by an IIROC member firm must have completed the Canadian Securities Course (CSC), the Conduct & Practices Handbook (CPH), and the 90 day Investment Advisor Training Program (IATP).
Within 30 months of becoming licensed, the registrant is further required to meet the post-licensing proficiency requirement by passing the Wealth Management Essentials course (WME).
A Registered Representative is also required to complete 30 hours of professional development (product knowledge) and 12 hours of compliance training every three year continuing education cycle as set out by the Investment Industry Regulatory Organization of Canada (IIROC).
To trade options and/or futures, a Registered Representative must pass the Derivatives Fundamentals Course (DFC) in addition to the Options Licencing Course (OLC) and/or the Futures Licensing Course (FLC), or alternatively, the Derivatives Fundamentals Options Licensing Course (DFOL) for options.