2020 Antares Contact serial number

Can anyone help decode this serial number? I know that the top numbers are the year and that it was the 2219th saddle made and I know that 3A is the flap and 18 is the seat, but what on earth does 2+2 mean? I’m guessing 26 has something to do with the tree, but I’m not entirely sure. Any thoughts? image|375x500

And if the image doesn’t work it reads:

Antares
Contact

20 2219
3A/2+2
18 26

From what I know about Antares flaps:

The 20 is year of manufacture (which you know, is 2020)
The second number is location of manufacture I believe

3A is a long slightly forward flap
Not sure about the 2+2!

I assume the 26 is seat width (Antares seat usually come in 24, 26, or 28) and 18 is size.