R.G.D. stands for Registered Graphic Designer, and it is the official designation of the Registered Graphic Designers of Ontario.

This excerpt from the official RGD web site explains what the association is:

RGD Ontario was created by an Act (Bill Pr56) of the Ontario Legislature in 1996 to grant graphic designers who qualify the right to use the designation Registered Graphic Designer (R.G.D.). RGD Ontario is the only graphic design association in North America to have this kind of legislation.

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And this excerpt from the official RGD web site explains the designation:

A Registered Graphic Designer and R.G.D. is a graphic design practitioner, manager or educator who has met the Association’s qualification criteria and has been granted the right to use these professional designations. No one else may use the designations Registered Graphic Designer or R.G.D. Persons in Ontario who are not Registered Graphic Designers are not excluded from practicing graphic design. The R.G.D. and Registered Graphic Designer designations are signals of quality and competence to the profession, the public, and the government.

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By hiring an R.G.D. qualified graphic designer, you have the assurance of professionalism and quality that you expect from a graphic designer.

Source: clover road