The UEFI Forum has released the v2.8 specification for UEFI. March not only had the 2.8 release, but a 2.7b release. The last release, 2.7, was in August 2017.

https://uefi.org/specifications

Click to access UEFI_Spec_2_8_final.pdf

Below are list of changes from 2.7b and 2.8, from the Revision History section of the spec.

[The Mantis Number is the entry in the bug database which has all the details on the change, only UEFI Forum members have access to that data,  all that is shown in the public spec is the Mantis Number and Bug Title. Non-members will need to use this Description String to try and find the updated section in the spec and look for recent Tianocore implmentation code checkins, or maybe wait for Nikolaj to issue a series of Tweets…]

Revision Mantis Number / Description Date
2.8 1832 Extend SERIAL_IO with DeviceTypeGuid
2.8 1834 UEFI REST EX Protocol
2.8 1853 Adding support for a REST style formset
2.8 1858 New Device Path for bootable NVDIMM namespaces
2.8 1861 New EFI_MEMORY_RANGE_CAPSULE Descriptor
2.8 1866 GetInfo() of Adapter Information Protocol should have a provision for IHV to return no data
2.8 1872 Peripheral-attached Memory
2.8 1876 Remove the EBC support requirement
2.8 1879 Clarification of REST (EX) protocol
2.8 1908 Update of uncommitted data in the FOROM_OPEN callback
2.8 1919 Memory Cryptography Attribute
2.8 1920 Redfish Discover Protocol
2.8 1921 HTTPS hostname validation
2.8 1924 Update to EFI_REST_EX_PROTOCOL.AsyncSendReceive
2.8 1925 Clarify requirement of REST related protocols
2.8 1926 New UEFI Spec Revision –> 2.8
2.8 1935 UEFI JSON Capsule Support
2.8 1936 ResetSystem – support ResetData for all status scenarios.
2.8 1937 Behavior of default values
2.8 1941 New EFI REST JSON Structure Protocol
2.8 1942 Adding dependency expression capability into FMP type capsules
2.8 1947 Keyword strings of Configuration Keyword Handler Protocol Enhancements
2.8 1953 Add document version# conventions
2.8 1954 set (*Attributes) when GetVariable() returns EFI_BUFFER_TOO_SMALL and Attributes is non-NULL
2.8 1956 Platform to honor ActionRequest for Action changing
2.8 1961 Add EFI_UNSUPPORTED to EFI_RUNTIME_SERVICES calls
2.8 1966 Add new capsule processing error codes
2.8 1974 Add new CCIX PER Log Error Section to appendix
2.8 1996 Firmware Processing of the Capsule Identified by EFI_JSON_CAPSULE_ID_GUID
2.7B 1773 Clarify The EFI System Table entry for capsule image
2.7B 1801 ExtractConfig() format may change when called multiple times
2.7B 1835 Misleading / unclear statement about EFI-bootability of UDF media
2.7B 1838 RGB/BGR Contradiction in 2.7 GOP
2.7B 1841 BluetoothLE ECR – support autoreconnect
2.7B 1842 BluetoothLE ECR – Add missing ConnectionCompleteCallback
2.7B 1843 HTTP Example Code Update
2.7B 1844 Replace obsoleted RFC number with new number for TCP
2.7B 1845 Clarification on AIP types “Network boot” and “SAN MAC Address”
2.7B 1846 EFI_LOAD_FILE2 requirement
2.7B 1865 Adding clarification in EFI_NOT_READY for ReadKeyStrokeEx()
2.7B 1869 Clarify FMP buffer too small behavior
2.7B 1874 Add RFC3021 to reference in uefi.org
2.7B 1875 Clarify platform specific elements in chapter 2.6.2
2.7B 1878 Errata – Make DHCP server optional for HTTP boot
2.7B 1880 Arm binding EL2 register state clarification
2.7B 1890 EfiMemoryMappedIO Usage Clarification
2.7B 1897 Clarification on mapping of UEFI memory attributes to ARM memory types and paging attributes
2.7B 1899 Errata: Clarify EFI_INVALID_PARAMETER for FMP->GetImageInfo()
2.7B 1901 GPT Protective MBR description
2.7B 1902 CapsuleImageSize Clarification
2.7B 1903 Root Directory File Name
2.7B 1906 ACPI Table Pointer Installation
2.7B 1908 Update of uncommitted data in the FOROM_OPEN callback
2.7B 1923 Syntax error in EFI iSCSI Initiator Name Protocol
2.7B 1957 Request to add status code EFI_DEVICE_ERROR for ExtractConfig
2.7B 1964 Print disclaimer for all future UEFI specs
2.7B 1987 incorrect VLAN_CONFIG_SET function definition