Comments in BibTex

You can "comment" whole entries by erasing the @ in front of the type declaration (@book -> book); there are no other ways of commenting parts of entries. However, unknown fields are ignored, so you can say

OPTpages={34--35},

in order to ignore the pages field. Also repeated fields are ignored.

---

As a matter of fact, text between entries will be ignored, which is why the above works; only what appears between the braces like in

@ENTRY{...
  ...
}

is considered. However, it should be noted that Biber is stricter than BibTeX in this respect, so it will warn about what it considers junk between entries. Adding a % at the beginning of a line turns off Biber's warnings.

Emacs uses the prefix '@Comment' when using the "comment-or-uncomment-region" command in a BibTex file. This works on any line (at least in my version).

Using '%' also works for me, but I remember having it not work once -- I guess it may not be the most compatible.

Otherwise, you can achieve a similar effect to commenting out by changing the strings: (1) Change the key of a whole bibtex entry to something else, or (2) change the name of a BibTex field, as BibTex ignores field it doesn't know. In particular, I often "comment out" fields by prepending an underscore to the field name, e.g., I include

_pages = { TODO },

to mark that I should add the page number later.