No documentation for 'l' and 'h' match codes

Output match files from TFM can include match codes of 'l' (lower-case L) and 'h' in addition to the documented 'p', 'c', 'n', 'b', and 'u' codes.  The source 'common/internal.h' notes:

l = (deinterlaced c bottom field)

h = (deinterlaced c top field)

At least a mention in the documentation seems essential and some further explanation would be welcome.