In IIS I can configure my custom error pages.
For each HTTP Error code I can say where to go. Several codes have a number of "sub" codes available. For example 404 has a regular 404, 404;1, 404;2 and so on..
What are they for? When are they returned? Should I make custom pages for these errors? Can I somehow easely configure all code "families" to come to the same page?