Periods are the smallest dab of ink on the page, but they’re some of the most important marks. Without periods paragraphs become very difficult to read, discouraging readers who have to sleuth around for the beginnings and ends of sentences. And abbreviations—a.m.—start to look like words—am.
Being such tiny things, periods do occasionally wander off unnoticed, and editors who insert an equally small dot of red pencil to put them back may find that their corrections go missing in action, too. That’s where the proofreaders’ mark for inserting a period—a circled dot—comes in very handy:
And circling a comma indicates that a period should be inserted in its place:
That red pencil still burning a hole in your pocket protector? You can find a full listing of all the Word Blog’s Proofreaders’ Marks entries here.