CURLSWebSocketFrameMBS.kFlagBinary = 2

Type	Topic	Plugin	Version
const	CURL	MBS CURL Plugin	23.0

One of the flag constants.

This is binary data.

CURLSWebSocketFrameMBS.kFlagClose = 8

Type	Topic	Plugin	Version
const	CURL	MBS CURL Plugin	23.0

One of the flag constants.

Close this transfer.

CURLSWebSocketFrameMBS.kFlagContinue = 4

Type	Topic	Plugin	Version
const	CURL	MBS CURL Plugin	23.0

One of the flag constants.

This is not the final fragment of the message, which implies that there will be another fragment coming as part of the same message where this bit is not set.

CURLSWebSocketFrameMBS.kFlagOffset = 32

Type	Topic	Plugin	Version
const	CURL	MBS CURL Plugin	23.0

One of the flag constants.

This is a partial fragment.
The provided data is only a partial fragment and there will be more in a following call to WebSocketSend(). When sending only a piece of the fragment like this, the fragsize must be provided with the total expected fragment size in the first call and it needs to be zero in subsequent calls.

CURLSWebSocketFrameMBS.kFlagPing = 16

Type	Topic	Plugin	Version
const	CURL	MBS CURL Plugin	23.0

One of the flag constants.

This as a ping.

CURLSWebSocketFrameMBS.kFlagPong = 64

Type	Topic	Plugin	Version
const	CURL	MBS CURL Plugin	23.0

One of the flag constants.

This is a pong.

CURLSWebSocketFrameMBS.kFlagText = 1

Type	Topic	Plugin	Version
const	CURL	MBS CURL Plugin	23.0

One of the flag constants.

The buffer contains text data.
Note that this makes a difference to WebSocket but CURL itself will not make any verification of the content or precautions that you actually send valid UTF-8 content.