Diplomacy: Theory and Practice, 5th ed.  –  Online updating pages

Chapter 3: ‘Around-the-Table’ Negotiations

p. 44, formula stage: When the ‘framework agreement’ on the Iran nuclear question was announced in early 2015, following many years of negotiations, it was also described as an agreement providing ‘key parameters’ for a final, detailed settlement.

Further reading: additions and links

‘Iran nuclear deal: negotiators announce “framework” agreement’, The Guardian, 3 April 2015