HR renewal in SAP Portal

hi,

I am new to implement HR renewal with Portal.

We have a requirement to add 2 ECC clients to SAP Enterprise Portal 7.4.

I created 1 ECC system with alias (SAP_ECC_HUMANRESOURCES), and everything works normally. But in order to create another system I need to mention a different alias?

So is this alias mandatory or can I go ahead and try with a different alias, something like SAP_ECC_HUMANRESOURCES_TEMP.

Also I could see some applications when clicked, uses standard alias supplied by SAP like SAP_HCM_PROXY, SAP_PROCUREMENT.

So would changing this alias work? or is there some thing to be done from portal / SAP side??

Thanks and Regards,

Sajith