Finally, business writing seems to observe certain stylistic conventions. These conventions may vary slightly from business to business, but are basically the same across the United States. Through this exploration, I see that there are other elements of good usage I could have examined, but chose not to. A variety of advice on writing is available, but there is not one definitive rule or even one handbook to which a writer must strictly adhere. There are guidelines a writer might consider, but ultimately, the writer must adapt his or her writing according to each writing situation.
Rules are guidelines meant to be helpful.
When rules cease to be helpful or become too dogmatic, disregard.