Water Hammer caused by toilets

In Terry Love’s WWWBoard I found the following post:

Hi:
We are being tormented by a water hammer that started suddenly. Everything was fine, and then one day the toilet got clogged. I freed the clog with a plunger, no problem. But now every time that toilet is flushed, we get the “water hammer” effect. We can stop it by opening another valve in the same line (turn on the bathroom faucet), but I’d sure like to know how to fix it for real. Any suggestions?

Here is the answer:

It sounds like the fill valve has a quick “off”.
Try adjusting the fill valve to let water in more slowly. This may be done, depending on the model, either at the top of the fill valve (ball cock) or by turning down the water volumn at the wall supply. In worst cases, you can add a mini-rester at the wall shutoff. Terry

There is a lot of information on water-hammer as you can see here on Google.