As you can see from the examples below, I have run across a total of four kinds of unique IDs for AXSections attributes, so far, after examining a limited sample of applications; namely, AXContent, AXContentNavigator, AXTopLevelNavigator, and AXSearch. From these, and from the nature of the standard UI elements that are associated with them, I suspect that AXSections is a new attribute designed to categorize key functional sections of any application window into a very small number of core operations that are common to most applications, to help assistive applications guide users to the most important parts of any application window.
I still don't understand why the AXSections attribute would be settable.
If this is a permanent addition to the Accessibility API, I urge Apple to document it, including in the Accessibility Definitions file at /System/Library/Accessibility/AccessibilityDefinitions.plist.
Finder:
AXContent (content) is <PFUIElement: 0x60000026ef80> {
AXDescription = path;
AXHelp = "<null>";
AXRole = AXList;
AXRoleDescription = list;
AXSubrole = "<null>";
AXTitle = "<null>";
}
AXTopLevelNavigator (top level navigator) is <PFUIElement: 0x628000071d80> {
AXDescription = sidebar;
AXHelp = "<null>";
AXRole = AXOutline;
AXRoleDescription = outline;
AXSubrole = "<null>";
AXTitle = "<null>";
}
AXSearch (search) is <PFUIElement: 0x620000070640> {
AXDescription = Search;
AXHelp = "<null>";
AXRole = AXTextField;
AXRoleDescription = "search text field";
AXSubrole = AXSearchField;
AXTitle = "<null>";
}
TextEdit:
AXContent (content) is <PFUIElement: 0x61000006c980> {
AXDescription = "<null>";
AXHelp = "<null>";
AXRole = AXTextArea;
AXRoleDescription = "text entry area";
AXSubrole = "<null>";
AXTitle = "<null>";
}
AXTopLevelNavigator (top level navigator) is <PFUIElement: 0x6280000783c0> {
AXDescription = "text alignment";
AXHelp = "<null>";
AXRole = AXRadioGroup;
AXRoleDescription = "radio group";
AXSubrole = "<null>";
AXTitle = "<null>";
}
Xcode:
AXContent (content) is <PFUIElement: 0x610000070540> {
AXDescription = "BrowserTabItemViewController.swift";
AXHelp = "<null>";
AXRole = AXGroup;
AXRoleDescription = group;
AXSubrole = "<null>";
AXTitle = "<null>";
}
AXSearch (search) is <PFUIElement: 0x6080000704c0> {
AXDescription = "Project navigator filter";
AXHelp = "Show files with matching name";
AXRole = AXTextField;
AXRoleDescription = "search text field";
AXSubrole = AXSearchField;
AXTitle = "<null>";
}
AXContentNavigator (content navigator) is <PFUIElement: 0x618000074180> {
AXDescription = "Project Navigator Outline";
AXHelp = "<null>";
AXRole = AXOutline;
AXRoleDescription = outline;
AXSubrole = "<null>";
AXTitle = "<null>";
}