"Corridor" Problems

If an asset class is outside of its corridor, does it have to get re balanced to its target strategic asset allocation, or just so that it is inside the corridor? In a Schweser example, International Equity has a Strategic Asset Allocation of 25%, corridor of 23.125% - 26.875%, but the closing allocation is only 23%. So does it need to be re balanced up to 23.125%, or back to 25%?

If an asset class is increasing rapidly and the manager does not want to sacrifice all of the upside potential they can re-adjust the portfolio just inside the corridor and not all the way back to the original. But this is a rebalancing risk similar to tracking risk.

Ultimatey rule of thumb states you should balance back to original target allocation. If it states something along the lines of not wanting to sacrifice future gains then just rebalance inside corridor.