Hotspot Network Scan List Filtering
An important function of the Hotpot Helper is to perform Wi-Fi scan list filtering. In the Wi-Fi pane in the Settings app, the user can browse the list of nearby Wi-Fi networks. A Wi-Fi network is annotated with the name of any Hotspot Helper that claims to handle that network. This name gives the user a visual cue that the network is one worth selecting over one that does not have an annotation.
The annotations are determined by the Wi-Fi scan list filtering process. The system asks each Hotpot Helper to provide feedback about the nearby Wi-Fi networks by issuing a kNEHotspotHelperCommandTypeFilterScanList command containing a list of Wi-Fi networks. In its response, the Hotpot Helper specifies every network that it supports with any confidence.