[Ipopt] The meaning of Number

[Brad Bell]

I am new to Ipopt and am looking at the documentation for "Coding the 
Problem Representation", which can currently be found at
    http://www.coin-or.org/Ipopt/documentation/node32.html
My first question is if this node number is fixed, or it may change with 
time (and hence the link above will not be correct for future versions 
of Ipopt) ?

The type "Number" is used in this section. For example, see
    http://www.coin-or.org/Ipopt/documentation/node36.html
Where are the specifications for this type ?