Well, pegs with a defined fluctuation boundary aren't that uncommon, for example, Danish Krona currently is pegged to Euro in such a manner - where it's pegged to within +/- 2.25% of a specific rate.
In essence, if you declare a plausible intent of keeping a rate near 1$ by accepting limitless orders to buy it at 0.98$ and sell it at 1.02$, and can keep that promise, then that's a decent peg.
In essence, if you declare a plausible intent of keeping a rate near 1$ by accepting limitless orders to buy it at 0.98$ and sell it at 1.02$, and can keep that promise, then that's a decent peg.