SAN FRANCISCO — Don't yell, don't swear, don't flip the bird — and don't insult anyone's mother.

When some 70,000 fans converge on Candlestick Park this Sunday for the Bay Area's first NFC championship in 15 years, they had better be on their best behavior or risk being booted from the stadium — without warning.

Authorities say they won't tolerate a repeat of the threats and harassment that Saints fans complained about during last weekend's playoff game. That nail-biting 36-32 win had 49er fans cheering, and jeering at those wearing the New Orleans black and gold.

More security cameras and undercover police officers will be in place to identify abusive fans. Season ticketholders have been warned. Both teams and the NFL say they have adopted extraordinary measures.