At the bottom of the Request Pattern page is a table entitled Mappings. It appears to encapsulate a lot of useful information, however there is no guidance or key to the meaning of the contents.

One might guess that the table overall describes the match between the attributes of the Request pattern, and the Resources that conform to the pattern. However the meaning of the entries in the cells is opaque. What do 1C, 1N or E signify?

For the table to be useful, it needs to be provided with a guide to the overall meaning, and a key to the codes used in the table cells.