LOS ANGELES » Little Bo Peep would make the cut at the Halloween parade at Riverside Drive Elementary School here on Friday, but the staff she used to menace her sheep would probably have to go.

Guns, daggers and other toy weapons have long been excised from costumes at many school celebrations on Halloween. But in some classrooms across the country, the interpretation of what is too scary—or offensive, gross or saddening—is also leading to an abundance of caution and some prohibitions.

In a school district in Illinois, students are being encouraged to dress up as historical characters or delicious food items rather than vampires or zombies. In Texas, a school has issued suggestions for “;positive costumes”; for the annual Halloween dance. At Riverside Drive, a Los Angeles public school in the San Fernando Valley, the Halloween parade is being defanged right down to its jagged fingertips.

“;We're balancing a tradition here with the times we live in,”; said Tom Hernandez, a spokesman for District 202 in Plainfield, Ill., where costumes depicting animals and food (preferably carrots or pumpkins) are in favor.

Even at a public school named after the man who practically invented cloak and daggers for children, there are restrictions.

“;Children are not allowed to bring any weapons or masks to the costume parade, no swords, and they can wear moderate face makeup—nothing extreme,”; explained Addys Gonzalez, the office assistant at the Walt Disney Elementary School in Burbank, Calif.

A memo about costume appropriateness sent home recently by Riverside Drive's principal made the following points:

» They should not depict gangs or horror characters, or be scary.
» Masks are allowed only during the parade.
» Costumes may not demean any race, religion, nationality, handicapped condition or gender.
» No fake fingernails.
» No weapons, even fake ones.
» Shoes must be worn.

Joel Bishoff's children will make the cut at Riverside Drive. His second-grader will be Dorothy (not the witch!) from “;The Wizard of Oz,”; while his fifth-grade son will wear a costume depicting a box of Wheaties.

“;I'm not sure what is driving this memo,”; Bishoff said. “;But perhaps it is reaction to years past. Sometimes kids will have those 'Scream' masks, but usually not too blood and gutsy. I mean, can't parents have discretion? The fact is, if parents are too stupid to not send kids to school with hockey masks as Jason, they are probably too stupid to read this memo.”;

Jennifer Kessler, the principal at the Riverside Drive school, did not return calls seeking an explanation of the policy. Riverside Drive goes beyond the Los Angeles Unified Public Schools guidelines, written a few years ago, said Monica Carazo, a spokeswoman for the system. Those guidelines discourage fake weapons, costumes that mock race or gender and anything too sexy; French maids are explicitly discouraged.

Parents and some educators said that restrictions like those at Riverside Drive often stem from a desire to protect smaller children from freakishly scary costumes, to maintain classroom order (spray-on hair color is often banned, for instance, because kids tend to spray it all day long) and to keep from demeaning groups through costumes that play on stereotypes.

Some other institutions have taken a similar approach. The Chicago Children's Museum has imposed costume restrictions on employees for several years. Jennifer Farrington, the museum's president, said the restrictions had “;emerged out of talks about diversity and stereotypes.”;

“;This is about staying true to our vision and values, and developmentally appropriate practice, not about being politically correct,”; Farrington said, citing her own memo on the topic some years ago. “;We're about honoring and promoting diversity, not feeding children images of stereotypes.”;

In some school districts, there are other motivating factors.

“;Several years ago, there was some push back in our community,”; said Hernandez, the school district spokesman in Plainfield, Ill. “;Some people thought Halloween was a satanic ritual. Well, let's not say satanic—let's say they were not comfortable with what it represents.”;

Still, no one in Plainfield wanted the Halloween celebrations, a long tradition in the school community there, to end. So guidelines were formed in favor of costumes that “;portray positive images,”; Hernandez said.

“;If someone shows up in a witch costume, we're not going to tell them to take it off,”; he said, but the district will not countenance claws of any sort.

The change in costume mores has not been lost on those who make a living selling dress up.

“;I would say people are becoming more classical and creative and staying away from things like Chucky,”; said Shelly Shai, the owner of Shelly's Dance & Costume Wear in Los Angeles, referring to a character in a series of horror films. “;I think they have enough of that in daily life now with the movies that come out, which seem to only get worse and worse. And when it comes to dressing up, people don't want to be one of a million vampires anyway.”;

At James F. Bay Elementary in Seabrook, Texas, costumes are forbidden outright, according to the school's principal, Erin Tite, but an exception was made for the Halloween dance.

“;The purpose for the dance was to allow them a safe place to wear their costumes in place of Trick or Treating for some of our students,”; said Tite in an e-mail message. “;We established the guidelines of 'positive costumes' from the beginning, knowing what we might see if we chose not to establish boundaries.”;