Help understanding what "Pattern A, Pattern B", etc mean

I'm sure this has been talked about before, but I've been unable to find concrete answers...

I have a 2012 Impala (LFX V6, 6T70 trans) and would like to have a better understanding of what the different "Patterns" represent under the Trans->Auto Shift Speed tab...

I have different shift point tables for: "Normal" (what I normally adjust), "Pattern A, Pattern B, Hot, Tap Up Tap Down and Safety Shifts".

They are mainly self explanatory, except for "Pattern A" and "Pattern B" - when are they used?

Also - the "Normal" tables have a "D1" and "D2" table, but the "Pattern A" and "Pattern B' only have a "D2" table. What are the D1/D2 tables for and why is D1 missing from Pattern A and Pattern B?

Please help - I'm confused!!!! :-)

Thank you!

Anyone?

Is there really any way to know for sure what "Pattern A" and "Pattern B" represent and if they're actually used on your specific car?

Thanks in advance!