open punctuation is omitted closed punctuation is a colon
Mixed Punctuation means simply applying a colon at the end of any salutation.
open punctuation is used in types of business letters. In a business letter you may address the letter, but instead of putting somthing like San Diego, California, you would put SAN DIEGO CALIFORNIA....
Open Punctuation are omitted.
its wher the pincuation is open with no tabs and closesd with a p