Control channels carry information and indicators from the user equipment (UE), such as uplink control information (UCI) messages. UCI messages support the scheduling of uplink shared channel (UL-SCH) transmissions. UCI messages are encoded and transmitted through the physical uplink control channel (PUCCH) or are multiplexed onto the physical uplink shared channel (PUSCH). For an overview of the available PUCCH and PUSCH functionalities, see Uplink Physical Channels. UCI encoding and decoding are available for polar coding and channel coding of small block lengths.