| Value | Meaning |
|---|---|
| none0 | |
| fallback1 | Use hardcoded fallback to detect icon theme name depending on the current desktop environment. Has lower priority than other methods. |
| gtk22 | Use gtk2 settings to detect icon theme name. Has lower priority than gtk3. |
| gtk34 | Use gtk3 settings to detect icon theme name. |
| automaticfallback | gtk2 | gtk3 | Use all known means to detect icon theme name. |