I think that this is simply a designation for what we would call in American English the "Clerk of the Court."

--------------------------------------------------
Note added at 1 hr (2010-09-24 15:52:28 GMT)
--------------------------------------------------

See e.g.:

Escambia County Court
Clerk of the Court

In Escambia County traffic ticket matters are heard in County Court. The major cities of Escambia County include: Century, and Pensacola ...

http://fltrafficlaws.com/id82.html

--------------------------------------------------
Note added at 1 hr (2010-09-24 15:53:53 GMT)
--------------------------------------------------

The Judicial Branch of Arizona
Pinal County

Clerk of the Court

The Office of the Clerk of the Court is committed to providing Quality customer service, ensuring the integrity and access to court records by supporting the Judicial process through efficient Records Management, Financial Administration and Jury Service.

http://pinalcountyaz.gov/Departments/JudicialBranch/Clerkoft...

--------------------------------------------------
Note added at 1 hr (2010-09-24 15:54:52 GMT)
--------------------------------------------------

All executions must be signed by the clerk of the Court where the judgement was entered, the County Clerk of the home county, or a New York State licensed attorney.

http://www.monroecounty.gov/sheriff2-civilbureau

--------------------------------------------------
Note added at 1 hr (2010-09-24 15:59:27 GMT)
--------------------------------------------------

This resource may prove helpful. Depending on who is issuing the document, you may just want to use "clerk" by itself:

FRONT DESK JUSTICE: INSIDE AND OUTSIDE CRIMINAL PROCEDURE IN MEXICO CITY*

Catalina Pérez Correa**

"What´s your name?" —the clerk (oficial secretario) at the Public Prosecutor´s Office asked him.

http://info8.juridicas.unam.mx/cont/mlawrns/1/arc/arc2.htm