IEEE 802.1D is the Ethernet MAC bridges standard which includes bridging, Spanning Tree Protocol and others. It is standardized by the IEEE 802.1 working group. It includes details specific to linking many of the other 802 projects including the widely deployed 802.3 (Ethernet), 802.11 (Wireless LAN) and 802.16 (WiMax) standards.
Bridges using virtual LANs (VLANs) have never been part of 802.1D, but were instead specified in separate standard, 802.1Q originally published in 1998.
By 2014, all the functionality defined by IEEE 802.1D has been incorporated into either IEEE 802.1Q-2014 (Bridges and Bridged Networks) or IEEE 802.1AC (MAC Service Definition). 802.1D is expected to be officially withdrawn in 2022