Straightforward corrections were written in one colour (red); queries in a second colour (I think this was blue); and later in the week, when final layouts were being assembled, proofreaders would note in a third colour (green) any optional additions or deletions which the story's author or editor had suggested. These options could be used or not, depending on the story 'fit', or number of lines available for that story in the page's layout. As no one except authors and editors were allowed to make such deletions or additions, having readymade options available helped to minimise the need to send 'copy' back up to the author during later stages in page make-up. In fact, the name given to these optional types of annotations came from the ink used: they were known as 'greens'.
The partner in each team who read from the original text read everything: punctuation ('bang' for exclamation point, I remember; 'pos' for apostrophe, 'query' for question mark), capital letters (cap-A etc.), spellings of most proper nouns, new paragraphs, indentations, quotation marks etc. So the first line of text in this article would be read as follows:
para cap e each two hyphen person proofreading one word team at open itals cap t time cap m magazine close itals worked according to a well hyphen established and tightly controlled routine stop
Very occasionally, a galley would come back with a ‘thank you’ from the writer who had been saved from embarrassment by an astute query. But the proofreader whose query was found to be groundless was punished royally. Trailing miles of galley behind him, and maybe carrying a book from the exhaustive Time Library to show that his was the correct version of the fact in question, the writer would sail triumphantly down the long 24th-floor corridor into the proofreaders’ windowless rabbit warren (only the writers had windows) and in a loud voice that everyone this side of the central elevator shaft could hear announce: ‘Thank you for your efforts but my version was the correct translation of that line from the Gallic Wars. You were probably confusing the dative and the ablative, but thank you anyway.' No wonder proofreading partners consulted carefully before querying.
This was the final article in a series about my first job in the publishing industry. In more than 40 years' involvement in publishing since then, I have never known a proofreading process of equivalent comprehensiveness. For that matter, I've never worked in any organisation that had such well-developed processes for the preparation and production of printed material.