The term Kodak is an invented term; the best arrangement of alphabets for a trademark. Invented term has the strongest chance for being registered due to its distinctiveness. Remember that trademark is suppose to help consumers to associate a brand with its product origin.
On this day, September 4, 1888, George Eastman applied for the registration of Kodak, prior to the founding of Kodak Company in 1892. The letter "K" had been a favorite alphabet of George Eastman. Together with his mother, he devised the name Kodak with an anagram set. He used three principal concepts to create the name:
1) It must be short
2) It could not be mispronounced
3) It could not resemble anything else or be associated with anything other than itself.
The 'Kodak' trademark is a successful brand because it is short and simple. It uses only two syllables to pronounce. Consumers would have low chances of mispronouncing or misspelling the term. The third principle resonates with trademark laws; that a mark should be distinctive.