The global settings are set both in the "Workplace Shell" object and on the "XDesktop" notebook page and are stored in the "XWorkplace" app in OS2.INI. All the global notebook logic is in src\shared\notebook.c.

Note that the large structure called GLOBALSETTINGS that was used from XFolder 0.1 until XWorkplace 0.9.16 is gone now. Yes, it almost broke my heart, but I got sick of it. Instead, global settings are implemented via cmnQuerySetting and cmnSetSetting in src\shared\common.c now.

By contrast, the individual object settings are stored in instance data, which is declared in the .IDL files. Most of these are stored and retrieved using the normal WPS mechanism (wpSaveDeferred/wpRestoreData) and can have a certain "transparent" value, which means that the global setting is to be used instead.