The purpose of this website

What is written here is general information. It is not advice of any professional kind and takes no account of an individual reader's position.

Mistakes and changes

Anything load-bearing - a number, a rule, a mechanism - is worth confirming at the primary source first. Nothing here is warranted as fit for that purpose.

External links

External pages change without notice. A link that was accurate when it was added may point somewhere different now.

Changes

This is not a permanent text. Check this page for the current position.

If something here is wrong

Queries about a point covered on these pages may be sent to [email protected].