cgeo/c-geo-opensource — comment on commit 6caa8a1897c5eee0f039f745033eaf1bc30c8256
File:  line 0
By Bananeweizen:

The new flag exists only since API level 5. That's why I don't want to risk that older versions can't read it (or do something unexpected). The filter flag works also for older API levels, but the other flag is the recommended one. Additionally there are some devices out there which are reported to only work correctly (i.e. not use auto suggestion), if both flags are specified.
So to sum it up: This seems the most effective way of implementation, even if there is a more easy (non API compatible) declarative way.