Heavy Flak - 88 or 105 mm heavy guns

[George Hopp]

There was some inconsistency over the German numbering system. They were restricted in developing new armaments after WW1, so up to the mid-30s often gave a spurious number like "18" to indicate that it had been developed during WW1 and was therefore permitted.

As I recall the original 88 did come out in 1918. So as I said above, the numbering appears to reflect the year the weapon became operational.