InstallAware

While investigating patch installers, I tried to get a better understanding of the installer settings mentioned below.
I have summarised the tooltips and manual entries (InstallAware12) below, with two questions.

Project Options, Project, Product Code (this has a 'New' button).
Tooltip: Each product must have a unique code. Different versions of the same product can have the same product code to be recognized as part of the same product family.
Manual: The product code uniquely identifies your installation to the Windows installer. It must be unique in each different product, as well as different versions of the same product.
Q. "Different versions of the same product can have the same product code to be recognized as part of the same product family." seems to contradict the second part of "It must be unique in each different product, as well as different versions of the same product."; which is correct?

Project Options, Project, Upgrades Product with Product Code: (AKA Upgrade Code)
Tooltip: The Upgrade code is used in patching. Every product you wish to patch, and the patch itself, must have the same upgrade code.
Manual: If your installation upgrades a previous version, enter the product code of that version here.
Q. In a non-patch situation, should this be blank? Or the same as the Product code?
A. I think it should be the same as the Product Code, but it should not matter unless we are patching.
Q. It seems odd that the manual entry shown above does not mention patching.

Project Options, Project, Summary, Revision Code
Tooltip: Every setup must have a different revision code, even different builds of the same version. The IDE automatically changes the revision code each time you do a new build.
Q. This field has a Generate button -- why, when would I want to press it?

Dear NickDay,

Q. "Different versions of the same product can have the same product code to be recognized as part of the same product family." seems to contradict the second part of "It must be unique in each different product, as well as different versions of the same product."; which is correct?

Honestly, I don't see the contradiction.
This means that an IDENTICAL and UNIQUE product code is required for a product to be reconized as part of the same product family and even different versions of the same product, if part of the same product family, requires an IDENTICAL and UNIQUE product code. Otherwise, it will be recognized as a different product.

Q. In a non-patch situation, should this be blank? Or the same as the Product code?

It must be the same "UPGRADECODE" (... not the PRODUCT CODE) for the same product family. This code is only used by patch, but it is good practice to the same even with "non-patch situation" ... in the event that you decide later to use a patch.

Regards

Thanks for your reply, Francesco,

To explain what I found confusing:
When the manual says "It must be unique in each different product, as well as different versions of the same product.
I read this as 'it must be unique in different versions of the same product'. I.e. it MUST be a DIFFERENT code in different versions of the same product.
Whereas the tooltip says "Different versions of the same product CAN have the SAME product code". Do you see what I mean? Maybe it's clearer in more recent versions of the manual.

Anyway I now understand that they must be identical in different versions of the same product to be recognised as belonging to the same product family, thank you.

Regards