Here is an explanation:
"If you receive a Compensatable Fail – Module overall grade E4 at level one or level two you are advised to wait until you receive your results for the year before deciding whether to resit a module for which you get an E grade. If you obtain 90 credits at the level at which you are studying you will be compensated for this marginal failure in modules worth 30 credits. If you have fewer than 90 credits you will have to resit some of the modules you have marginally failed with E grades."
http://www.wlv.ac.uk/PDF/aca_ugregs_faqs.pdf
This still doesn't spell out exactly what "compensation" means, but it is clear that you can be credited in certain circumstances for modules you have narrowly failed without having to resit them.