Even back in the day when I was still doing some bookkeeping and payroll work, the work had to be double-checked - that is a variation of proofreading.
In the latter half of my working life, I worked for some government contractors. That, of course, required quite a bit of proofreading.
These days, I do, on a volunteer basis, our senior mobile home community's monthly newsletter. I've been its editor and publisher for over 12 years. Even though this is a rather casual newsletter for a casual readership, and I do not sweat small grammar errors, I do sweat factual errors.
So, I have 3 proofreaders. We have over 400 homes in our community and they depend on the accuracy of what they read each month.
Ok - so here's the deal. Over the years, yea, decades, of proofreading, I have learned the hard way that no matter how many proofreaders you have, there will still be an error or two that escapes everyone's scrutiny. It happens. All the time.
Now, I just printed all 400+ copies of the September issue, 6 pages (3, double-sided). I have this awful feeling of dread. All my proofreaders said "clean copy," "good copy," "nothing wrong."
That makes me very nervous.
Last year, the one time that happened, all the copies got into all the hands of the eager residents. only to find out that I had reported that our park management was in the process of "renovating the poor area."
You can imagine how shocked my neighbors were to find out we had a poor area in our community.
True, we have lots of senior on fixed income - but not poor. You guessed it - it was supposed to read the "pool" area.
So, I'm crossing my fingers, toes and eyes, and saying a wee prayer, that this issue really is clean copy.
So, my personal Proofreader's Theorem: Any work that passes the inspection of more than one proofreader will contain a blatant error evident to the first layperson who views that work.