plural or singular

There was a good discussion on a similar subject the other day. Here's a link.

http://www.grammarly.com/answers/questions/11155-the-singular-they/#answer_15039

I avoid using the third person plural, whether objective, nominative, or possessive with a singular antecedent. The context of the use would be critical to whether it would be acceptable, but as a rule, no.

But everyone will agree that 'I' is capitalized every time.