If this option is not checked, then Technicians will be able to change the Accuracy of the Group specs during a Calibration. 

Most Companies Will check this option to prevent technicians from setting the specs a little wider to avoid a Failing entry.

Example - The Spec Limits for a Calibration Group are +/- 0.05 and during the Calibration the Technician is getting one reading that is off by 0.06

Calibration Points tab

Test Results tab

Test Results tab with Company option Not checked and 'Modify Specs'

If the Company Option is checked, then Technicians will Not be able to adjust the specs during a Calibration.

Note - Changes made to the Test Points tab, if allowed, will Never change the master record.