|Curse Redirected To Myself|
I want to use something I think is copyrighted/trademarked in my novel/story/project?
For example you want to write about someone drinking coca cola in your novel. That's perfectly ok, you don't have to write a polite letter asking for permission. Can I please use your product in my story? Yes, you can. Let the people in your story drink as much coke as they want. One exception: Defamation. No, coca cola is not made with human blood. You can't write it is in your novel, because this harms the company and the product. You won't be charged for copyright infringement, you'll be sued for defamation.
I want to cite something from another story, my character wants to read a passage from another book. Is this copyright infringement?
Under terms, no. You have to stylize it as quoted. You have to explicitly mention its source and do not have the right to claim its contents as your own.
Can I use a name from another story in my own story?
Eep, stop. This one's a pitfall. If the name is commonly used, yes (most names on the behindthename.com databases are this). If the name is unique (for example Gandalf), no. There's an exception to this once more. If you explicitly state that the name originates from the source (for example a character was named after the character from a book, because the book also exists in your writing universe). A character named after Gandalf is ok, if The Lord of the Rings is a book that exists in your universe and you state it so.
I've heard about coined words. Can these be used freely?
Coined words, or words created by an author, also known as neologisms, can be used freely. Unlike names, authors have little power over these words. So the word snark (C.S Lewis) can be used in your novel.
How do I preserve my own copyright?
The greatest issue for any writer.
Placing something in public domain ruins your copyright. The internet, newspapers, media (unless you got paid for publishing and got a contract) are usually considered public domain.
The best way to keep your copyright for yourself is finishing your novel and only ever sending it partially out to publishers. Letting other people proofread is ok, but outside the public domain.
Special thanks to Uncle Orson's Writing Class and the explanations of legalese terms on wikipedia.