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  • Claude THIMBERLAY thinks this is interesting:

Note that Figure 1-5 shows the location of the most significant byte and least significant bit in each byte. IEEE documentation lists Ethernet addresses with the most significant byte on the left. However, inside each byte, the leftmost bit is the most significant bit, and the rightmost bit is the least significant bit. Many documents refer to the bit order as canonical. Regardless of the term, the bit order inside each byte is important for understanding the meaning of the two most significant bits in an Ethernet address:

From

Cover of CCIE Routing and Switching v5.0 Official Cert Guide, Volume 1, Fifth Edition

Note

Errata :

According to Figure 1-5, within each byte of a MAC address, the most and least significant bits are the leftmost and rightmost bits, respectively. When an Ethernet frame is transmitted, its bytes are sent in their usual order but the bits in individual bytes are transmitted in the reverse order, least significant bit first. The FCS field is the only exception to this rule. Many documents refer to this reversed bit order as canonical. The two least significant bits in the first byte of a MAC address are of special significance: