-e --ed Output unmerged changes from OLDFILE to YOURFILE into MYFILE.
-E --show-overlap Output unmerged changes, bracketing conflicts.
-A --show-all Output all changes, bracketing conflicts.
-x --overlap-only Output overlapping changes.
-X Output overlapping changes, bracketing them.
-3 --easy-only Output unmerged nonoverlapping changes.
-m --merge Output merged file instead of ed script (default -A).
-L LABEL --label=LABEL Use LABEL instead of file name.
-i Append `w' and `q' commands to ed scripts.
-a --text Treat all files as text.
-T --initial-tab Make tabs line up by prepending a tab.
--diff-program=PROGRAM Use PROGRAM to compare files.
-v --version Output version info.
--help Output this help.
If a FILE is `-', read standard input.
This program comes with NO WARRANTY, to the extent permitted by law. You may redistribute copies of this program under the terms of the GNU General Public License. For more information about these matters, see the file named COPYING.
should give you access to the complete manual.