Adjustment u/s 143 (1)(a)

the assessee has received an adjustment notice whereby under the descripttion it is written
in schedule part b-ti exemption under clause of section 10 or exemption u/s 13b is claimed against heads of income in slno 13v of schedule part BTI. Assesses should have enter only taxable income in schedule hp, cg, bp and os.
what does this error descripttion means kindly help.
while filing the return income under the schedule os was shown and properly exemption was claimed.