What does "See the Partner's Instructions" mean on the K-1 instructions, and where are they?

This means that there is a longer description of what goes into a particular field than the IRS wanted to put into the list of codes for the member K-1. The full document is a little over 14 pages, and can be found as a .pdf file on the IRS web site at:
https://www.irs.gov/pub/irs-pdf/i1065sk1.pdf