Apple provides and recommends use of Install OS X Mountain Lion.app
- that is, "the app" – in its entirety.
For Build 12A269 for OS X 10.8, the version of the app is 1.3.12 (351).
Ignoring parts of the app – with
- installation may succeed.
(The same is true for Lion when parts of Install Mac OS X Lion.app are not used for installation.)
Unknown for Mountain Lion
The full list of:
- things that do not occur, things that may not succeed, when installation is attempted or performed with something other than the app.
My initial plan is to accept an answer that provides either:
- the fullest list; or
- the best set of evidence for a partial list.
com.apple.Boot.plist(5) OS X Manual Page – page dated March 17, 2011 for 10.7.4, the same date appears on the page within 10.8.
For Mountain Lion on some types of hardware, there may be a unique distribution (ESD).