Why this website exists

What is set out here is a description of how something works. A description cannot stand in for advice that accounts for someone's own situation.

Where links lead

No link here should be read as approval. It notes where else the subject appears, and that is all it means.

How current this is

Where a figure, rule, or mechanism matters to a decision, check it against the primary source before relying on it. That is not a use this material is warranted for.

Changes

Should any of it change, the revised text replaces the old as soon as it appears here.

If something here is wrong

Write to [email protected] about the accuracy of something published here.