The "Annotations" are taken from Charles Sayle's (1912) edition of the Works of Thomas Browne, Vol. 1, as corrected by reference to the 1672 edition. Mr. Sayle notes that "the Annotations upon the Religio Medici, which were always reprinted with the text during the seventeenth century, are here restored. They will appeal to a certain class of readers which has a right to be considered." After that somewhat back-handed statement, he goes on to mention that some of the quotations in the notes have been corrected, but that to correct all of them would involve more time and effort than it was possible to devote to the task. Well can I believe this; it has taken quite some time to get them even to the state you will find here.
Simon Wilkin reproduces some of these notes in his edition of Religio Medici (marking them "Keck" or "K"). Bund, in the Harvard Classics edition found widely on line, reproduces (uncritically and without specific attribution) some of the information found in some of the notes.
Links in the Keck annotations are of three sorts: the main links, reproductions of Browne text from the beginning of a paragraph to the square bracket (this reproduced from the original editions) will take you to the corresponding part of Religio Medici, which will open in a window called "text". The "Annotations" window will remain open. Links in the text, e.g., "Pliny (Prefat. Nat. Hist.)", will take you to the source, or something close to it. These links will open in a new window. Finally, numbered links, of the form 13, will take you to notes at the bottom of the page (which in turn are linked back to the text). These are textual notes, more complicated source notes, Keck's marginalia, commentary, and so on.
This page is maintained at the University of Chicago by James Eason, who welcomes comments, criticism, and suggestions.