We call them “letters to the editor,” but that’s not quite right.

I’m the editorial page editor at the Press Herald, but what you see in the opinion section aren’t letters to me. And they aren’t letters to Assistant Editorial Page Editor Sarah Collins, who does most of the work it takes  to get them ready for publication. 

They are really “letters to readers” from other readers with something to say. Sometimes writers want to add an insight that they feel was missing from our reporting. Sometimes they want to put a a different spin on a fact that’s been in print.

Sometimes they just want to sound off.

All are welcome. Despite the bad news you may have heard about the newspaper business, one number that never seems to drop is the number of people who want their letter published by us. Even though there are more opportunities than ever for people to publish their opinions, readers still want to see their work show up in our forum. 

And they want to do it even though, unlike the internet, we have rules.

There’s length — in this newspaper, letters are limited to 300 words or fewer. Writers can’t be anonymous and letters can’t be libelous, obscene or engage in personal attacks. 

And they have to be true. 

That doesn’t mean I have to agree with the opinions expressed. Everybody has the right to be wrong (a right I exercise often). But any fact that is used to support an opinion needs to be an actual fact. 

And that’s where we run into trouble. Where’s the line between fact and opinion — the one between what you believe and why you believe it?

There are a number of issues where these distinctions get murky. Lately, the attempts to blur the lines surround vaccines.

In March, Maine voters will be asked to strike down a new law that eliminates religious and philosophical opt-outs from vaccination requirements for students, health care workers and people who work with children.

Under the old law, Maine has had some of the least restrictive vaccine requirements in the country and some of the highest opt-out rates. Not surprisingly, we also have high rates of infectious diseases, even leading the nation in whooping cough. 

People who didn’t want to give up their right to send unvaccinated children to school got the issue on the ballot and with the help of a well-funded national “vaccine hesitancy” community.

Fine. Both sides will get their chance to make their cases and everyone will get a chance to vote. We have had letters from both sides already, and I expect that we will have more.

What we won’t have are letters that echo a series of Facebook ads that are being sent by a well-financed anti-vaccine organization into the newsfeeds of people who may be voting in the Maine election.

Those ads spread misinformation about vaccines, claiming, without evidence, that vaccines cause harm and don’t really stop the spread of disease. They also claim that the scientific evidence that shows the benefits of vaccines are fraudulent, perpetrated by “Big Pharma” and some invented “medical-industrial complex.”

You won’t see those claims in a letter to the editor, though. Because they are not true.

This is not censorship, or a violation of anyone’s free-speech rights — only the government can do that. It doesn’t mean that there will be no pro-referendum letters allowed. There are fact-based arguments against limiting vaccine opt-outs, and even if I think the other side has a stronger case, we all learn from listening to the whole debate.

But if someone could prove that there really were a deadly pro-vaccine conspiracy, you wouldn’t learn about it in a brief item on the opinion page. It would be a Page One story that would probably win the Pulitzer Prize. But false allegations won’t be sneaking into the newspaper disguised as opinion.

Even though we are living in divided time, there are few places where people with different opinions actually come into contact. The letters to the editor space is one of them, and we don’t want to lose it.