(4)In order to take account of technical developments on financial markets, and notably the increase in the use of indexes as underlying of structured securities, certain requirements of Regulation (EC) No 809/2004 should be reviewed and clarified. By conferring the responsibility to compose the index on another entity of the group, issuers could circumvent the requirement to include in the prospectus a description of the index composed by the issuer (item 4.2.2 of Annex XII) and thus avoid liability where the description is inaccurate. Accordingly, that requirement should also be extended to indexes composed by an entity belonging to the same group as the issuer.