MaxShow(210) is replaced with DisplayQty(1138). The iceberg orders cannot be fully invisible anymore. Setting the DisplayQty (1138) = 0 is interpreted as no hidden volume, i.e. the full order quantity is displayed to the market. Omitting the field gives the same result.
Execution Reports (8): added nonmandatory tag RefreshQty (1088)
Support for non-printable ASCII characters (such as control characters ranging from 0x00 to 0x1F) in string values has been removed to ensure compliance with the WS/REST API. Attempting to use non-printable ASCII characters will now result in a decoding error.
Execution Reports (8): added nonmandatory tags MMPGroup (9019), QuoteSetID (302), QuoteID (117), QuoteEntryID (299) related to Mass Quoting
Added Quote Cancel (Z)
Mass Cancel Report (r): added one more type for MassCancelRequestType, added optional field QuoteCancelType for mass cancel reports generated by Quote Cancel (Z), ClOrdID is not required tag anymore
Fixed an issue where Reject (3) was incorrectly returned instead of OrderCancelReject (9), with the specified ClOrdID, DeribitLabel, or OrigClOrdId, in response to an Order Cancel Request (F).
added the following messages: TradeCaptureReportRequest (AD), TradeCaptureReportRequestAck (AQ), and TradeCaptureReport (AE). Clients can now utilize these to subscribe for receiving reports on their own trades.
added fields NoTickRules(1205), StartTickPriceRange(1206), TickIncrement(1208) to the instrument for tick size steps
added option DisplayIncrementSteps(9018) to Logon and Security List Request(x) so the client can enable receiving the above mentioned new fields in the instrument
added possibility to use client’s ClOrdID and DeribitLabel in Order Cancel Request(F), Order Mass Cancel Request(q) and Order Cancel/Replace Request(G) without exchange generated OrigClOrdID (equivalent of REST/WS cancel_by_label etc)