In California, Penal Code 626.10 applies, with SEPERATE rules for K-12 (subsection "A") and Universities (subsection "B"). The difference between "A" and "B" is so subtle you might miss it: in "B" you can pack any length FOLDER you want, including concealed in the folded position. While it's not explicit, you can bet that Penal Codes 653k and 12020 still apply!
I'll quote the actual code below. Following 626.10 I'll quote 626 where it defines exactly what constitutes the various types of schools. This should be all you need.
Upshot: I carry Sifu#1 (5.5" blade folder) on University grounds with no qualms.
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626.10. (a) Any person, except a duly appointed peace officer as
defined in Chapter 4.5 (commencing with Section 830) of Title 3 of
Part 2, a full-time paid peace officer of another state or the
federal government who is carrying out official duties while in this
state, a person summoned by any officer to assist in making arrests
or preserving the peace while the person is actually engaged in
assisting any officer, or a member of the military forces of this
state or the United States who is engaged in the performance of his
or her duties, who brings or possesses any dirk, dagger, ice pick,
knife having a blade longer than 21/2 inches, folding knife with a
blade that locks into place, a razor with an unguarded blade, a
taser, or a stun gun, as defined in subdivision (a) of Section 244.5,
any instrument that expels a metallic projectile such as a BB or a
pellet, through the force of air pressure, CO2 pressure, or spring
action, or any spot marker gun, upon the grounds of, or within, any
public or private school providing instruction in kindergarten or any
of grades 1 to 12, inclusive, is guilty of a public offense,
punishable by imprisonment in a county jail not exceeding one year,
or by imprisonment in the state prison.
(b) Any person, except a duly appointed peace officer as defined
in Chapter 4.5 (commencing with Section 830) of Title 3 of Part 2, a
full-time paid peace officer of another state or the federal
government who is carrying out official duties while in this state, a
person summoned by any officer to assist in making arrests or
preserving the peace while the person is actually engaged in
assisting any officer, or a member of the military forces of this
state or the United States who is engaged in the performance of his
or her duties, who brings or possesses any dirk, dagger, ice pick, or
knife having a fixed blade longer than 21/2 inches upon the grounds
of, or within, any private university, the University of California,
the California State University, or the California Community Colleges
is guilty of a public offense, punishable by imprisonment in a
county jail not exceeding one year, or by imprisonment in the state
prison.
(c) Subdivisions (a) and (b) do not apply to any person who brings
or possesses a knife having a blade longer than 21/2 inches or a
razor with an unguarded blade upon the grounds of, or within, a
public or private school providing instruction in kindergarten or any
of grades 1 to 12, inclusive, or any private university, state
university, or community college at the direction of a faculty member
of the private university, state university, or community college,
or a certificated or classified employee of the school for use in a
private university, state university, community college, or
school-sponsored activity or class.
(d) Subdivisions (a) and (b) do not apply to any person who brings
or possesses an ice pick, a knife having a blade longer than 21/2
inches, or a razor with an unguarded blade upon the grounds of, or
within, a public or private school providing instruction in
kindergarten or any of grades 1 to 12, inclusive, or any private
university, state university, or community college for a lawful
purpose within the scope of the person's employment.
(e) Subdivision (b) does not apply to any person who brings or
possesses an ice pick or a knife having a fixed blade longer than
21/2 inches upon the grounds of, or within, any private university,
state university, or community college for lawful use in or around a
residence or residential facility located upon those grounds or for
lawful use in food preparation or consumption.
(f) Subdivision (a) does not apply to any person who brings an
instrument that expels a metallic projectile such as a BB or a
pellet, through the force of air pressure, CO2 pressure, or spring
action, or any spot marker gun upon the grounds of, or within, a
public or private school providing instruction in kindergarten or any
of grades 1 to 12, inclusive, if the person has the written
permission of the school principal or his or her designee.
(g) Any certificated or classified employee or school peace
officer of a public or private school providing instruction in
kindergarten or any of grades 1 to 12, inclusive, may seize any of
the weapons described in subdivision (a), and any certificated or
classified employee or school peace officer of any private
university, state university, or community college may seize any of
the weapons described in subdivision (b), from the possession of any
person upon the grounds of, or within, the school if he or she knows,
or has reasonable cause to know, the person is prohibited from
bringing or possessing the weapon upon the grounds of, or within, the
school.
(h) As used in this section, "dirk" or "dagger" means a knife or
other instrument with or without a handguard that is capable of ready
use as a stabbing weapon that may inflict great bodily injury or
death.
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626. (a) As used in this chapter, the following definitions apply:
(1) "University" means the University of California, and includes
any affiliated institution thereof and any campus or facility owned,
operated, or controlled by the Regents of the University of
California.
(2) "State university" means any California state university, and
includes any campus or facility owned, operated, or controlled by the
Trustees of the California State University.
(3) "Community college" means any public community college
established pursuant to the Education Code.
(4) "School" means any elementary school, junior high school,
four-year high school, senior high school, adult school or any branch
thereof, opportunity school, continuation high school, regional
occupational center, evening high school, or technical school or any
public right-of-way situated immediately adjacent to school property
or any other place if a teacher and one or more pupils are required
to be at that place in connection with assigned school activities.
(5) "Chief administrative officer" means either of the following:
(A) The president of the university or a state university, the
Chancellor of the California State University, or the officer
designated by the Regents of the University of California or
pursuant to authority granted by the Regents of the University of
California to administer and be the officer in charge of a campus or
other facility owned, operated, or controlled by the Regents of the
University of California, or the superintendent of a community
college district.
(B) For a school, the principal of the school, a person who
possesses a standard supervision credential or a standard
administrative credential and who is designated by the principal, or
a person who carries out the same functions as a person who possesses
a credential and who is designated by the principal.
(b) For the purpose of determining the penalty to be imposed
pursuant to this chapter, the court may consider a written report
from the Department of Justice containing information from its
records showing prior convictions; and that communication is prima
facie evidence of the convictions, if the defendant admits them,
regardless of whether or not the complaint commencing the proceedings
has alleged prior convictions.
(c) As used in this code, the following definitions apply:
(1) "Pupil currently attending school" means a pupil enrolled in a
public school who has been in attendance or has had an excused
absence, for purposes of attendance accounting, for a majority of the
days for which the pupil has been enrolled in that school during the
school year.
(2) "Safe school zone" means an area that encompasses any of the
following places during regular school hours or within 60 minutes
before or after the schoolday or 60 minutes before or after a
school-sponsored activity at the schoolsite:
(A) Within 100 feet of a bus stop, whether or not a public transit
bus stop, that has been publicly designated by the school district
as a schoolbus stop. This definition applies only if the school
district has chosen to mark the bus stop as a schoolbus stop.
(B) Within 1,000 feet of a school, as designated by the school
district.
