We know what it means in the obvious sense, but not the whys and wherefores .......
According to Julie Halls at TNA, she believes that it refers to some very old 'Correspondence', and that the '641/2195' was the Board of Trade reference for that correspondence - which if we could see it, would explain all. What it meant and whether this correspondence still exists seems apparently to be unknown and unlikely.
Although I've accidentally deleted my picture of the Representations page for 160988, I have photographed other virtually identical pages where the original drawing or photo is no longer present, and a similar 'Corr.' written note is all that remains ................ see the attached pix.
However, in these other examples you'll see there is a rubber stamp comment which says 'Cert. not Issued'. etc.
........ so does that explain the absence of our missing picture/drawing for 160988 - i.e. it was an unsuccessful Registration, and as such the factory image was removed from the Representations page. I know nothing about pavement lights or their invention etc., so can't comment as to the possibility that there may have been some problems with validity of such a Registration.
Unfortunately, I now can't remember if the page for Rd. 160988 also said 'Cert. not Issued'.
I might look again some day.