* `GtkIMContextSimple` reads compose sequences from the first of the
* following files that is found: ~/.config/gtk-4.0/Compose, ~/.XCompose,
* /usr/share/X11/locale/$locale/Compose (for locales that have a nontrivial
- * Compose file). The syntax of these files is described in the Compose(5)
- * manual page.
+ * Compose file). A subset of the file syntax described in the Compose(5)
+ * manual page is supported. Additionally, `include "%L"` loads GTK’s built-in
+ * table of compose sequences rather than the locale-specific one from X11.
*
* If none of these files is found, `GtkIMContextSimple` uses a built-in table
* of compose sequences that is derived from the X11 Compose files.