Originally Posted by
skywardhunter
Simple IT. Are you able to log in to your account by entering an email instead of a number? Then there you go, it needs to uniquely identify an account. Also as a basic means of ensuring people don't register multiple accounts.
And also idf an indexed key field value in a database. Needs to be unique
nb
I used to have KLM for both me anf girlfriend on same email. Signon later enabled for email-id along side 9x numeric NNNNNNNNN member number, and of course could not use as not unique as shred to both accts