Just a few corrections
4= designation for units assigned to the unincorporated areas of east
county. All county patrol units not assigned to a contract city in
east county are designated 4. West county units are designated 3.
East county runs from the conejo grade, newbury park, oakpark, bell
canyon, santa susana knolls grimes canyon and 118 to sand canyon.

E- stands for the area. you are right that at one time there was a
F-frank area and it was incorporated with the E units. this has
changed back. there are now f-frank cars assgned out of the moorpark
station. the 3- stood for the shift, the 4 stood for what beat they
worked.

4-east county E-beat- 3-shift- 4- area assigned.