Just to be clear, these rules are sort of meant to be broken, at least when it comes to websites. For example, your teachers always told you to write in complete sentences, but on the web–where perhaps only 28% of the words are actually read–a sentence fragment or two might be both acceptable and appropriate.
Writing for the Nielsen Norman Group, Hoa Loranger explains why a one-sentence paragraph is OK and that it’s OK to break that old rule about writing out numerals less than 10. She suggests that to improve scannability and comprehension on the web, writers should adjust their writing to the situation:
The rules that you can violate depend on the context, the target audience, and the brand or tone of voice. For example, the tone applied to professional publications is usually more formal than the tone of blog posts from the same company. Formal tone usually requires adhering to traditional writing conventions more closely, whereas conversational tone allows for greater flexibility (“Break Grammar Rules on Websites for Clarity“).
In about ten days, I’ll be meeting a new group of writing students. Although we will be learning the rules and characteristics of formal writing, I hope that by the end of the class we can talk about when it’s appropriate to break the rules. I can’t wait!