Patek Philippe

Anyone understand the system for these indications? Obviously there’s the large engraved B or D for buckle or deployant. But what do secondary *printed* letter 2numbers combos mean? I thought maybe matte vs shiny or thick vs skinny but by looking at the n... 

for the strap maker's names PP uses. They use several different companies.

For example E81 is an alpha code that tells the style, in this case 21x16 mm, deployant, padded 4.0 mm in material and color 100 which is dark chestnut shiny alligator with square scales. The maker is indicated by eg the printed ”CF” for Camille Fournet. ... 

I have it and A91 is 24x18 mm, tang buckle, flat (non padded) 2.5 mm, shiny alligator with square scales in color 100 which is black. It is for eg ref 5076 in platinum. I could not find the alpha code C34, are you sure it is correct?

Has anyone ever digities the catlog and uploaded it somewhere? And could you please help me with understand what A99 code is for?

Thank you for your response. It is super helpful. Though if I am not mistaken, A99 is some shade of Black alligator with square scales rather than dark brown. Also is the code of strap also for Calatrava Travel Time 5134G?

You're correct that 125 is for infact Matte Dark Brown. But then I think A99 should have a different color code instead of 125.