California case number ***** are not standardized. The abbreviation absolutely does not mean "not filed" (despite the silly answers by a wide range of attorneys on the internet who are simply guessing, rather than to admit ignorance.
More likely, the abbreviation represents the court division in the county (e.g., "North Fresno") -- or it may indicate the type of criminal case (e.g., "Nonviolent Felony").
The only way to be certain is to contact the court clerk and ask -- because, as I said, these codes are not standardized from one county to another.
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