Hmmmm. That's a poser. Perhaps I should refrain from being pedantic. However, I know you will appreciate constructive criticism in humourous form. Sooooooo.... perhaps you meant to ask, "What are the absolutes of writing well?

Sorry. I couldn't resist. I hope you did see the humour and that all is well and good.

Of course, the fact of the matter is old grammar rules and definitions are broken down every day. Modern writing is not so confined as my "example". I highly recommend realtively new texts dealing with "modern effective writing". While there are many simplistic changes as of late, such as "Here is..." instead of "Enclosed please find...", many of the texts delve much further into the topics raised in the posts above and are worth reading.

An engineering professor who taught me at Uni used to give us writing exercises that were gruelling! For example, he forbade the use of the word "the" in one research report. (Oops.... For example, he forbade use of the word "the" in one research report.) And, there were others. "That" was never allowed at any time. Paragraphs limited to three sentences.... etc... excellent brain exercise. Especially for lydexics me like.