This message notifies a peer about changes to protocol parameters. It follows the same format as [xversion](/protocol/network/messages/xversion) protocol parameters. Implementations **SHOULD** only send changed parameters, rather than every parameter. Note that some XVERSION parameters are not changeable and therefore will be ignored if they appear in this message.
See the [xversion fields](/protocol/network/messages/xversion#xversion-fields) for detailed information about each parameter.
## Message Format
| Field | Length | Format | Description |
|--|--|--|--|
| number of values | variable | [variable length integer](/protocol/formats/variable-length-integer) | The number of values being sent. |
| values | variable | `number_of_values` * [xversion values](/protocol/network/messages/xversion#xversion-value-format) | The list of values to communicate. |
