A recovery routine runs in the subspace environment that the previous routine was running in when it encountered an error or percolated.

After an error in the mainline program, the first recovery routine to receive control runs in the subspace that the mainline was running in at the time of error. If the mainline routine was running in Subspace A, the recovery routine gets control in Subspace A. If the mainline routine was running with full address space addressability, the recovery routine gets control with full address space addressability.

If the recovery routine percolates, the next recovery routine receives control in the environment in effect when the previous recovery routine percolated. For example, if the first recovery routine received control in Subspace A, issued the BSG instruction to change to full address space addressability, then percolated, the next recovery routine will receive control with full address space addressability.