"git log" with the "-p" option, they
do not produce the output described above; instead they produce a
patch file. You can customize the creation of such patches via the
-GIT_EXTERNAL_DIFF and the GIT_DIFF_OPTS environment variables.
+`GIT_EXTERNAL_DIFF` and the `GIT_DIFF_OPTS` environment variables.
What the -p option produces is slightly different from the traditional
diff format: