I have a recipe requesting pasta #2 as an ingredient. What is pasta #2? I searched in several places but found nothing useful.
This is most probably referring to the size of pasta of a certain type.
But you shoul be more detailed in your question, saying the type of pasta you refer to or the source where you got the receipt from.
If the pasta are noodles then you can bet it that they are talking about the size of pasta.
Pasta exist of many different kinds (at least here in italy), so pasta #2 is to us like saying "a car with comfortable chairs"...quite generic :-)
This link might help.