Simply refer to the trademark guidelines: they do not want the name to lose its brand character and become a generic denomination for any certified analyst.
Quote:
The CFA and Chartered Financial Analyst trademarks must be used as adjectives, not nouns, and the marks must not be used in the plural or possessive. To refer to “a Chartered Financial Analyst” or a group of “CFAs” is improper. Proper use under trademark law and the Standards of Professional Conduct would be to refer to “CFA charterholders” or “the Chartered Financial Analyst designation.” These rules flow directly from trademark law and CFA Institute efforts to prevent genericide. Genericide is the process by which a trademark loses its ability to function as a brand name and becomes the generic name of a particular type or category of product. Marks that are generic may be used by any group to describe their product. A mark becomes generic when it is used improperly by the public, the media or the mark owner. For example, calling any type of tissue a Kleenex®, or asking for a XEROX® of the report will lead to genericide. In contrast, proper use of the marks as adjectives, such as “Kleenex® tissues” and “XEROX® copiers,” identifies both the product class and the brand name. If generic use continues without serious efforts by the owner to curtail it, the brand name may become the generic product name. Proper use of the CFA and Chartered Financial Analyst marks will prevent them from becoming generic terms for any type of financial professional.