Technical correction: the proper designations are "DE-9" and either "DE-15" (if you're referring to the high-density three-row connector used for VGA) or "DA-15

Technical correction: the proper designations are "DE-9" and either "DE-15" (if you're referring to the high-density three-row connector used for VGA) or "DA-15" (if you're referring to the original lower-density two-row 15-pin connector). The second letter referred to the shell size, so a DE-9 and DE-15 had different numbers of pins arranged in the same-sided shell. Wikipedia has a good section on this: https://en.wikipedia.org/wiki/D-subminiature#Description.2C_nomenclature.2C_and_variants https://en.wikipedia.org/wiki/D-subminiature#Description.2C_.... The so-called "DB-19", on the other hand, had a nonstandard shell size, so it doesn't really have a proper name under the original system. Maybe "Dx-19".