The application can use precursor markers to label spectrum peaks that trigger data-dependent scans. The Precursor flags do not add text labels to the spectrum peaks but adds the precursor marker 
to the precursor scans.
Procedure
- Open an injection or a raw data file (see Open injections or raw data files.
- The Chromatogram view and Spectrum view open.
- Select the Spectrum view.
- Select the Ellipsis menu
to open the Display Options dialog box. - In the Labels area, select the Precursor flag checkbox.
- Select OK to apply the labels to the active spectrum or select Cancel to discard the changes.