use this code -
<li *ngFor="let parcel of dataSource;">
<span [hidden]="parcel.ID !== ''">{{parcel.refrence }}</span>
</li>
or
<li *ngFor="let parcel of dataSource;">
<span *ngIf="parcel.ID == ''">{{parcel.refrence }}</span>
</li>
syntax for hidden [hidden]
source
to share