Stihl chain side strap letter and number?

[timbrjackrussel]

Can anyone tell me what these letters and numbers example Q1 or T4 represent? They are on the side straps.
Thank you

 

[Philbert]

Don't know what the tie strap markings mean (production runs?).

Attached is information on 'decoding' other markings on STIHL chains.

Philbert

 

[timbrjackrussel]

Don't know what the tie strap markings mean (production runs?).

Attached is information on 'decoding' other markings on STIHL chains.

Philbert

Thanks Nice to have all the info in one spot.