Query:underwriting of shares and debentures

friends plz.solve my query. In underwriting of shares and debentures chapter,in some of examples firm underwriting deducted 1st out of gross liability,in some of the examples unmarked application deducted 1st out of gross liab.and in some of the example marked application deducted 1st out of gross liab. so friends i'm confused whether 2 deduct marked appli.or unmarked appli.or firm underwriting 1st 4m gross liab. plz.solve it..thanks in advance.