Mosaic Human Encodings
Human encodings are defined to provide uniform compatible ways for sharing data between humans and software.
bech32 is used in many of these due to its superior properties. Refer to the link.
Keys
Public keys are encoded with bech32 using the mopub
prefix.
Secret keys are encoded with bech32 using the mosec
prefix.
References are encoded with bech32 using the moref
prefix.