Reference
How to read a pair
Every page on this board is built the same way. Reading this one first will save you working the shape out from the pages themselves.
A pair is two things, named before anything else
The two halves appear side by side near the top of the page, each with a short line saying what it actually is. They are named first on purpose. A page that describes a situation and then reveals what it was leaves the reader guessing along with it, and guessing is the habit these pages exist to break.
The halves are never a symptom and a cause. They are two situations of equal standing that happen to produce the same picture. Neither is the normal one and neither is the alarming one until the page says which.
One test, and only one
Each page carries a single test. Not a set of indicators to weigh, not a list of things to check off, and not a score. One thing you can do or look at whose answer falls on one side of the pair.
This constraint does real work. A pair with no single test is a pair that has not been thought through, and there were several candidates that got dropped from the board for exactly that reason. If a page needs steps to carry out the test, it gives steps, but the steps are one test and they end in one answer.
Where a test only rules one side out rather than settling both, the page says so. A test that narrows things is still useful and pretending it decided the matter is not.
The cost is given twice because it is not symmetric
Getting a pair the wrong way round has two versions and they almost never cost the same. Reading a delay as a loss usually costs some worry and a wasted hour. Reading a loss as a delay costs the money and the time. Which direction is expensive changes from pair to pair, and knowing it is more useful than knowing the odds.
That is why every page gives both directions rather than saying which case is more common. Frequency is somebody else guess. Cost is a property of the situation and can be reasoned about honestly.
When you are unsure and the test does not resolve it, the right move is to act as though it is whichever side is cheaper to be wrong about. Every page tells you which that is.
Then what to do on each side
Two short answers, one per half. Concrete, and stopping short of anything about wording, because how to phrase a message is a different subject and not one this site touches.
What the pages will not do
- They will not say how often a case occurs, because nobody outside can count it.
- They will not say that any nexus market mirror is up. Nothing here is monitored and no check of any kind is run.
- They will not give you a percentage, a date, a username or a quotation. None of that was collected.
- They will not tell you how to get around a rate limit, a captcha or any other control.
The board holds forty one pairs across six groups. Every pair lists them in one table with the test beside each. The tests strips the pairs away and leaves the tests. The costs does the same for the direction that hurts.
Questions readers send about this pair
Why is there no severity rating on the pages?
Because a rating would be invented. Cost in each direction can be reasoned about from the situation. A number from one to five cannot, and it would look like a measurement.
Can a pair have three members?
Then it is not a pair and it is not on the board. Several candidates were dropped for that reason rather than being stretched to fit.