Write to the almanac
One address, read by the people who write this. Corrections are the post we most want — especially a specification that has moved since we dated it.
There is no form on this page, and there is no form anywhere on this site. Nothing here is connected to an email service or a database, and a form that quietly posts into nowhere while thanking you for getting in touch is a lie with a submit button on it. So: one address, and it goes to the people who write the pages.
What is genuinely useful to send
A specification that has changed. Manufacturers rewrite their product pages without notice, and a tank size or a warranty length that was right on the day we read it may not be right on the day you read it. Tell us which page and which figure and we will re-read the source.
A source we should have used, particularly a primary one. There are several places on this site where we printed nothing because we could not open a document or could not find a publisher's own statement of something. If you know where one of those lives, that is the most valuable post we receive.
A sentence that reads as advice. We work hard to keep this site describing what sources say rather than telling anybody what to do about their own mouth, and we do not always get the line right. If a paragraph here reads like an instruction, we want to know.
What we cannot answer
Anything about your teeth, your gums, your symptoms or your treatment. Not because we are being careful with ourselves, but because the answer does not exist at this distance: it requires someone who can look in your mouth, measure and sometimes take a radiograph. We will not guess, and a guess is the only thing we could offer.
If something in your mouth is swelling, if you have a fever with it, if it is hard to swallow or breathe, or if bleeding will not stop, that is not a letter — that is a call to a dentist or to urgent care today.
Commercial post
If you make or sell one of the devices discussed here, corrections to a specification are welcome on the same address and will be checked against your own published page. Requests to be added to the comparison, to have a figure removed, or to arrange any other kind of placement are read and declined.