As "Trotter"'s comment makes clear, it's hard to get all the errata in one go. And of all errata, it's the omissions, the things that got left out, that are the hardest to spot. In proof of which, I forgot yesterday to mention one important omission from the Acknowledgments: my friend David Bratman's name should have been included among the participants in the Tolkien Symposiums whom I thank on page xxxiii. I've learned a lot from David's presentations, and I always look forward to them.
In addition, while it's not an errata, if there's another edition of the book down the road I'd certainly want to add a name to the acknowledgments on page xxxiv: that of Kate Latham, who saw the book through the final stages at the publisher's.
As for the point raised by "Trotter" in his comment, yes I should have specified that while THE TWO TOWERS came out in 1954, the second printing I use as a reference copy dates from 1955. In fact, I find it interesting that my copies of both THE TWO TOWERS and THE RETURN OF THE KING, which I picked up during a research trip to Oxford in May 1987, both originally belonged to the same person: one Jay O. Eastwick,* who bought them in Teheran in March 1956. I've long known about Stanley Unwin's enthusiasm for selling British books throughout the Empire (or Commonwealth, as it'd become by that time), but it's one thing to read about something in THE TRUTH ABOUT PUBLISHING or THE TRUTH ABOUT A PUBLISHER and quite another to come across first-hand evidence of his strategy in action.
*[or possibly Guy O. Eastwick; can't quite read the handwriting]
2 days ago