+@defvar comment-end-can-be-escaped
+If this buffer local variable is non-@code{nil}, a single character
+which usually terminates a comment doesn't do so when that character
+is escaped. This is used in C and C++ Modes, where line comments
+starting with @samp{//} can be continued onto the next line by
+escaping the newline with @samp{\}.
+@end defvar
+