What is the traditional proofreading notation to indicate that an incorrect typeface has been used?

What type of error does this sentence have? "They walked along the Rio Grande River."

Which means "to deny under oath"?

Which spelled-out number is NOT hyphenated correctly?

Which is the term for the page on the left side in an open book?

Which work is likely not to be in the public domain in the United States?

What is an artist's board used for mixing paints called?

Britney Spears is going to keep on dancing...

Which sentence uses "too" correctly?

Which sentence is properly capitalized?

Which sentence uses "they're," "their," and "there" correctly?