Racism has never been one of the classic “Three R’s” of education, but a disturbing trend shows it may be more prevalent than anyone would like in local schools.

Fully one-third of all hate incidents reported to the Anti-Defamation League in 2005 took place at schools, ranging from graffiti to harassment, and running the gamut from grade school to colleges.

The number of reported incidents — 73 — and portion that took place at schools is almost exactly the same as the 2004 ADL Bay Area audit. Tami Holzman, the ADL’s regional assistant director, sees the statistics as neither good news nor bad news, but a clear indicator that on-campus situations need to be addressed (and the ADL has recently created the position of a campus coordinator).

Some incidents reported in Northern California in 2005:

• A San Francisco middle school teacher’s classroom was vandalized with anti-Semitic messages.

• An eighth-grade girl in Sacramento had threatening anti-Jewish voicemails left on her cell phone.

• An elementary school in Orinda was vandalized with messages like “burn Jews” and swastikas.

• El Cerrito High School was vandalized with racist and anti-Semitic graffiti.

• A middle school in Foster City was vandalized with sentiments such as “stupid Jews” and “f—-ing Jews” as well as the word “Jews” with a slash through it.

San Francisco County once again had the highest number of incidents with 23, followed by Alameda and Santa Clara counties each reporting six, and Contra Costa and San Mateo counties had five.

The number of incidents reported to the ADL was at a stagnant — though relatively high — level nationwide as well. All told, 1,757 incidents were reported in 2005, a statistically irrelevant 3 percent drop from the year before.