Patek Philippe

There is four-letter alphabet printed on the certificate of origin (eg. "APHN" on the pic.). Anyone can explain what this four-letter means? I guess this means the date of sales but I do not know how to read. John...  

It tells you when the watch was manufactured. P 0 a 1 t 2 e 3 k 4 h 5 r 6 o 7 n 8 s 9 For example: POPR=0706 -> Production month is July 2006 The new Certificates does not have this; these letter codes was stopped sometime around the summer of 2008.

thanks for your comment! so "APHN" means October 1958! how did you get this secret numbers. john

Does it make sense with October 1958? Got a picture of the watch?

october 1958 make sense! the watch is ref.2583 with 12-600. judging from the movement number year 1958 make sense. john

On to their certificates.

i have another certificate which has "PASS". this means 1999. when Patek stopped using these four letters?? should be after 2000. john