What is a re-entry permit (REP) and can this be renewed?

A REP allows SPRs to leave and enter Singapore as they wish. The REP is valid for 5 years and thereafter must be renewed.
The Electronic Re-Entry Permit system or e-REP in short, is an online, web-based system that allows SPRs to apply or renew online for a Re-Entry Permit (REP) or transfer the remaining validity of their REPs from an old passport to a new passport.