ST return link with 26AS

In this case, please reconcile your 26as income with ST3 form. Ideally both should match, however you can also be sure that appropriate amt of service tax is duly paid.
The main purpose behind such scrutiny is to ensure the correctness of assessment, checking the taxability, correctness of value of service u/s 67, effective rate of tax after taking into account any exemption notification or abatements, correctness of availing & utilisation of CENVAT credit.
The significant aspect of the aforesaid scrutiny is to ensure validation of the information furnished in self-assessed ST-3 with the intent to reconcile the information furnished in ST-3 with ITR Form 4/5/6 and 26AS.