The first Squier Strats serial number was engraved on the neck plate together with the writing “MADE IN CHINA” and started with the prefix NC or YN (Yako Nineties), followed by six numbers whose first two referred to the year.
The new Squiers Affinity and Standard, unveiled at NAMM in 1999, with rosewood fretboards, made in China in Yako plant, had the serial number that started with CY (which stood for China Yako), those made in Dallan Dongfang had the serial number CD (China Dallan); the fretted maple necks were made in Indonesia in the PT Cort factory and had the serial number which started with IC (Indonesia Cort). The Mini was an exception which, despite having a rosewood fretboard, was manufactured in Indonesia in the PT Samick factory and had the serial number that started with IS (Indonesia Samick).

PREFIXES OF THE CHINESE SQUIERS:
NC     “Made in China” 
          The first figure of a following 6 digit number provides year of production 
          For example: NC5xxxxx = 1995-1996​

YN     “Made in China”
          The first figure of a following 6 digit number provides year of production
          Made in Yako factory
          For example: YN5xxxxx = 1995-1996

CD     “Crafted in China”
          The first two figures of a following 8 or 9 digit number provide year of producion
          Made in Dallan Dongfang factory
          For example: CD99xxxxxx = 1999-2000

CY      “Crafted in China”
          The first or the first two figures of a following 8 or 9 digit number provide year of production
          Made in Yako factory
          For example: CY98xxxxxx = 1998-1999
          For example: CY08xxxxxx = 2008-2009
          For example: CY8xxxxxxx = 2008-2009
 
CT, CJ   “Made in China”, “Crafted in China”
              The first of the following numbers provides year of production
              Probably made in Yako factory (Taiwan)
 
CA     “Made in China”, “Crafted in China”
          The first of the following numbers provides year of production
          Probabilmente costruite nella fabbrica di Axl
 
CAE    (no country shown)
          The first two figures of a following 10 digit number provide year of production
          For example: CAE-08xxxxxxxx = made in 2008-2009
          Probably made in Axl factory

CXS   “Crafted in China”
          The first figure of a following 9 digit number provides year of production
          Made in Axl factory
          For example: CXS07xxxxxxx = 2007-2008
 
COS   “Crafted in China”
          The first two figures of a following 8 digit number provide year of production
          For example: COS10xxxxxx = 2010-2011
 
COB   “Crafted in China”
          The first two figures of a following 9 digit number provide year of production
          Unknown factory
          For example: COB09xxxxxxx
 
CGRL “Crafted in China”
          The first two figures of a following 8 digit number provide year of production
          For example: CGRL09xxxxxx = 2009-2010
 
CGS   “Crafted in China”
          The first two figures of a following 7 or 8 or 9 digit number provide year of production
          "S" stands for Squier
          For example: CGS10xxxxxx = 2010-2011

CGF   “Crafted in China”
          The first two figures of the following numbers provide year of production
          Used on the Modern Player Strats, "F" stands for Fender
          For example: CGF11xxxxxx = 2011-2012

CGRB, CGRJ, CGRK   “Crafted in China”
                                  The first two figures of a following 8 digit number provide year of production                                                                 Used since 2020

INDONESIAN SERIAL NUMBERS:
IC       “Crafted in Indonesia” - I = Indonesia, C = Cor-Tek (Cort),
          The first two figures of a following 8 or 9 digit number provide year of production
          For example: IC09xxxxxx = 2009-2010
 
IS       “Crafted in Indonesia” - I = Indonesia, S = Samick,
          The first two figures of a following 8 or 9 digit number provide year of production
          For example: IC02xxxxxxx = 2002-2003
 
ICS     “Crafted in Indonesia”
          The first two figures of a following 8 or 9 digit number provide year of production
          Usually used on Fender Special Run (FSR) strats made in Cor-Tek
          For example: ICS10xxxxxx = 2010-2011

SI       “Crafted in Indonesia”
          The first two figures of a following 8 or 9 digit number provide year of production
          For example: SI08xxxxxxx = 2008-2009

ISS     “Crafted in Indonesia” 
          The first two figures of a following 6 digit number provide year of production
          For example: ISS19xxxx = 2019