version (`%A`) and the other branches' version (`%B`). These
three tokens are replaced with the names of temporary files that
hold the contents of these versions when the command line is
-built.
+built. Additionally, %L will be replaced with the conflict marker
+size (see below).
The merge driver is expected to leave the result of the merge in
the file named with `%A` by overwriting it, and exit with zero
internal merge and the final merge.
+`conflict-marker-size`
+^^^^^^^^^^^^^^^^^^^^^^
+
+This attribute controls the length of conflict markers left in
+the work tree file during a conflicted merge. Only setting to
+the value to a positive integer has any meaningful effect.
+
+For example, this line in `.gitattributes` can be used to tell the merge
+machinery to leave much longer (instead of the usual 7-character-long)
+conflict markers when merging the file `Documentation/git-merge.txt`
+results in a conflict.
+
+------------------------
+Documentation/git-merge.txt conflict-marker-size=32
+------------------------
+
+
Checking whitespace errors
~~~~~~~~~~~~~~~~~~~~~~~~~~