*** Guide-to-Links ***
NM is used in various idiomatic number expressions: "He is
aged 70", "He is on flight 714". It is used, as well, for the
dollar sign "$" and other currency symbols. These symbol must 
make an NM connection forward to a number; it may then make act 
as a noun phrase, making an S, O, AN, or J connection.

         +---O--+               +--AN---+
         |   +NM+               +NM+
         |   |  |               |  |    |
      I have $ 30, but I want a $ 5000 car

Subscripts are used to indicate the type of modification:
NMa for letter modifiers:

        |      | 
     Vitamin D.id

The above uses the NM link because this kind of post-posed 
modification behaves the same way that post-posed numerical
modifiers behave.

NMn for numeric modifiers:

         |     |
     Flight.n 412

NMr for roman numerals:

       |    |     |
     Pope Pious XII.rn

NMw for spelled-out numbers:

        |     |
     Alpha.n one

Grammar Documentation Page.