I recently stumbled across undocumented Delphi directives that were used to set the PE OS headers.
They are as follows:
The usage for these directives are as follows:
{$SETPEOSVERSION major.minor} {$SETPESUBSYSVERSION major.minor}{$SETPEUSERVERSION major.minor}
These compiler directives were probably introduced at the same time that the command line compiler introduced these, which was probably in Delphi 2010.
In 2017, with the release of Delphi 10.2 Tokyo, Embarcadero introduced a specialized implementation of the Observer pattern into the System.Classes unit. While it has been in the wild for 9 years, it remains a "hidden" architecture for many, primarily because it serves as the invisible engine behind LiveBindings. Other than live bindings, you can also use the Observer pattern as a way to update component settings to the Windows registry, an .ini file, or persist it elsewhere.
System.Classes