Equating different filter numbers.
I've managed to get a bit confused recently while looking into the subject of filters for black and white and infrared photography.
On the one hand there is the B&W system of numbers and on the other there are things like Wratten numbers (American? Kodak?)
Is there a table available anywhere which shows where the various nomenclatures equate? I need this because if e.g. a book recommends a filter with a certain Wratten number, I need to be able to translate it to a B&W number as those are the filters which are most readily available to me.