This SAE Aerospace Recommended Practice (ARP) is intended to interpret and clarify engineering drawing requirements relating to the manufacture and inspection of fluid system couplings, tube fittings, and hose ends. Because it is impractical to define every minute detail of the part on the face of the drawing, this document describes interpretations of dimensioning of general machining features and otherwise undefined tolerances that fall under the heading of "good shop practice". This document serves as a supplement to engineering drawings when referenced on applicable documents.