Martin (1992: 198-9):
It remains to consider concessive relations, which will be taken here as crossclassifying manner, consequence, condition and purpose rather than as a fifth consequential category. The reason for this is that concessives function as a kind of "anti-modulation", cancelling the potentiality or obligation which would otherwise enable or determine the consequential relation between events.
The opposition is illustrated for manner relations in [4:79] and [4:80]; in [4:79] entering the right shows was enough to win, but in [4:80] the enablement is cancelled — entering the right shows was not sufficient to win.
MANNER[4:79] By entering the right shows,we won.
MANNER/CONCESSION[4:80] Even by entering the right shows,we didn't win.
 In SFL theory, the logical relation of concession is a type of condition, with the logical meaning of if P then contrary to expectation Q. As such, it does not cross-classify the other enhancement relations, as demonstrated more fully in tomorrow's posting.
 This confuses the logical relation of concessive condition with the interpersonal system of modality.
 This confuses interpersonal modality ("enablement") with sufficient conditions — here contrasted with insufficient conditions rather than necessary conditions.
 The logical relation here does not involve manner: means — N is by means of M. A manner agnate would be we didn't win by means of entering the right shows. The logical relation here is simply condition: concessive as in we didn't win even though we entered the right shows.