[3] Usage of the term increased after it was featured in the 1999 book Refactoring: Improving the Design of Existing Code by Martin Fowler.
[6] Code smells are usually not bugs; they are not technically incorrect and do not prevent the program from functioning.
Instead, they indicate weaknesses in design that may slow down development or increase the risk of bugs or failures in the future.
[1] Robert C. Martin calls a list of code smells a "value system" for software craftsmanship.
[7] Contrary to these severe interpretations, Cunningham's original definition was that a smell is a suggestion that something may be wrong, not evidence that there is already a problem.