Tag1 in the taint widget indicate which data should be marked. Having 2 tags allow you to mark differently some pieces of data, for example:
Tag0: rax Tag1: [0x123456; 8], rbx
This will follow the data inside
rax and mark with
Tag0 all of the locations that it goes through, and it will follow the data inside
[0x123456; 8] and
rbx and mark with
Tag1 all of the locations that it goes through. This allows to know if any tainted data comes from
You can see the results affecting each tag in the corresponding tab of the taint widget.
For more information, you can refer to the documentation on the taint widget.