Weird change to memory config in .cproject

[D_TTSA]

Good day

When I open project properties and navigate to C/C++ Build -> MCU settings, and click "Apply and close" without making any changes, I see that the highlighted value below changes.

What does this value represent?

Kind regards

[D_TTSA]

I would still like an answer to this question... @jingpan @kerryzhou