Each patch has a form attached to it where you outline a title, description (including your motivation), and a test plan. These are mapped into the eventual co

Each patch has a form attached to it where you outline a title, description (including your motivation), and a test plan. These are mapped into the eventual commit message. Individual, atomic ideas are expressed as a single diff which maps to a single commit. Representing one idea as multiple commits is discouraged, though Phabricator does keep its own history of how a patch evolves should you ever need to refer to it.