Default gender for pronouns [duplicate]

Possible Duplicate:
Is using “he” for a gender-neutral third-person correct?

I’m sure this is a duplicate, but I've heard that when the gender is unknown you are to use he instead of he or she.

Are there any references to support or discredit this? If so, what is the rule?

'He' is no longer the default pronoun. Many authors of finance related books will make a brief note in the preface that when a generic person is involved, he (the author) will use the female pronoun. I don't believe the rules we had 40 years ago to stay with male pronouns still applies.

Side note - on the school public announcement system, "whoever lost their jacket...." as I was sitting in my high school English class, I remarked on the plural pronoun and was told it was accepted as an attempt to be gender neutral. It was an all boys school.