I had a requirement to remove the BIEE version from the login page. Following is how it was done, let me know if you have another approach for this.
Make a backup of logoncontrolmessages.xml located in
OracleBI\web\msgdb\messages
and locate and remove the second occurence of sawm:param insert="2" /
Make a backup of logoncontrolmessages.xml located in
OracleBI\web\msgdb\messages
and locate and remove the second occurence of sawm:param insert="2" /
as illustrated below
Reboot your BI server and presentation service.
HTH