Keep Circulating the Tapes: To the extent where the 1969 release Great White Wonder is considered the Trope Codifier for unauthorized bootleg albums. Dylan was also (along with Frank Zappa) among the first artists to acknowledge the demand for unreleased music by releasing official versions of songs that hade been bootlegged for years. Still, even with eleven (and counting) volumes of the official Bootleg Series, there are still scores of unreleased songs, one out-of-print album (Dylan) and literally thousands of live recordings.
Meaningful Release Date: Tempest hitting the streets on September 11, 2012 was seemingly a nod to "Love and Theft" having infamously been released on 9/11/01. Coincidentally, Under The Red Sky was also issued on September 11 (way back in 1990, though).
Name's the Same: There was a Green Bay Packers defensive back named Bobby Dillon in the 1950s. There was also silent-era film director Robert Dillon, and a different Robert Dillon who was a screenwriter (Prime Cut, French Connection II). When a mutual acquantaince introduced Dylan to Robert Altman, Atlman wasn't familiar with Dylan or his work and mistook him for the screenwriter.
What Could Have Been: There was talk of Dylan recording an album backed by The Byrds in 1969, which made sense since they shared a label (Columbia Records) and a producer (Bob Johnston). But Dylan seemed to lose interest in the idea quickly, and The Byrds fired Johnston after just one album.
Dylan and The Band spent much of the summer of 1967 in the basement of their house, fooling around with covers and original songs, and recording snippets of it on an old tape machine. The Basement Tapes, as released 8 years later, contains only a handful of the songs recorded, often with obvious overdubs, and padded with The Band originals recorded years later. A lot of fans agree that some of the songs left off are among his best ever - or at least would have been if they'd been finished. It took until 2014 and the release of vol 11 of the Bootleg Series for most of the songs to see daylight.
Similarly, from 1974 (Blood On The Tracks) onward, Dylan has frequently second-guessed his studio performances, leaving off songs or performances from his studio albums that fans, critics, producers and backup musicians consider far better than what ended up on the album. Some of the more obvious examples include "Blind Willie McTell", "Mississippi", "Caribbean Wind", "Abandoned Love" and "Series of Dreams". A lot of these have since ended up on the various Bootleg Series releases.
Working Title: Blonde On Blonde boasts such classic tunes as "A Long-Haired Mule and a Porcupine Here", "What You Can Do For Your Wigwam" and "Seems Like a Freeze-Out"...or, as they ended up becoming, "Rainy Day Women #12 & 35", "Pledging My Time" and "Visions of Johanna".
Planet Waves was originally going to be called Love Songs, then Ceremonies of The Horseman (a Call Back to "Love Minus Zero/No Limit" from Bringing It All Back Home).