Those were the old rules, I think. The current T+Cs are pathetic:
Shell awarding is as follows:
Fill up in January, February, March Avios awarded in May
Fill up in April, May, June Avios awarded in September
Fill up in July, August, September Avios awarded in December
Fill up in January, February, March Avios awarded in March
Avios must be in your account by the end of each quarter to qualify for the bonus Avios for that quarter.
http://www.britishairways.com/travel...c/en_gb?#shell
So no purchases in October, November or December qualify, and January/February/March purchases get double credit. As if.
Did you say MUD? You're too gentle.