Your keyboard includes a
|trademark||alt 0153||option + 2|
|registered trademark||alt 0174||option + r|
|copyright||alt 0169||option + g|
When you need these symbols, use them. Don’t use goofy alphabetic approximations like (TM) or (c)—another typewriter habit.
Trademark symbols are set as superscripts—smaller characters positioned above the baseline of the text (Roxy’s Tacos™, Caring Is Our Business®). If you use proper trademark symbols, they’ll appear at the right size and height. No space is needed between the text and the trademark symbol.
Copyright symbols appear in line with the text (© 1999). Use a nonbreaking space between the copyright symbol and the year to ensure the two don’t end up on different lines or pages.
2021 MegaCorp Inc.
© 2021 MegaCorp Inc.
Must you put a word space after the copyright symbol? No, but it makes good sense semantically. The © directly replaces the word
Many word processors automatically substitute a symbol when you type (TM), (R), or (c). Consider turning off this feature, because references like Section 12(c) can be silently converted to Section 12©. The spell-checker won’t detect this error, and it’s easy to overlook while editing.
Copyright © 2021 is redundant. Word or symbol—not both.
I always use the nonitalicized versions of these marks, even if the adjacent text is italicized. I think it looks better. But that’s a preference, not a rule.