I know names are not copyrightable. BUT...as an example, Harry Potter, is a series and 'trademarked'. NOW...is a subtitle trademarked? Deathly Hollows.
Say I wanted to use my main series Deathly Hollows (I'm not just using it as an example) So would be Deathly Hollows: Ready to Run. (example) Would I be 'stepping on toes' if I use the subtitle as my main title?
Other example. The Vampire Diaries, S2E22 As I lay to die...They also refer it to the Mystic Diaries series.
Now "The Vampire Diaries" is trademarked since it is a 'series'. Could a series also induce another series within the original series and it be trademarked? (Mystic Diaries wasn't named in any of the titles, according to my research)
To the same question just put differently. Could a main title of a book or movie be "As I lay to die".
From my readings, 'generic' terms as if I had "Talk Diaries" - the work Diaries is a generic most commonly known word. And subtitles are not trademarked.
Another example: Twilight: New Moon - I know there is more than one book called Twilight. Since it is a widely used generic term. Could I name my main series New Moon: Deathly Dies
Again, IF, I read right. Series are trademarked AND single works. Twilight is a series but New moon is a single work since it goes with a single book.
I know a 'new' book series can't be called "Harry Potter" or "Vampire Diaries". Twilight is on the iffy end because it is a generic word.
With the examples used: Could a subtitle of an 'previously used' series be used as a main title on a 'new' series. Could a series "VP" have a trademark of another series within their series?
Thank you in advance!