asr. admin may i suggest to implement a rule in creating an user acct or parang may coding ang user acct.
example:
First-Surname (N-BangAsan)
or kong anong maisip nyong mas magandang pattern. para ma prevent ang double acct.
at syempre appropriate lang sa inyo yan kong pwede di na kami kasali dyan kc for sure di naman kmi magkakaroon ng double acct tsaka well known na mga user acct namin nla sr.