When the market of PC operating systems and disk tools grew and liberated, other vendors had a need to assign special partition types to their products as well.
[1] Several industry experts including Hale Landis, Ralf D. Brown, Matthias R. Paul, and Andries E. Brouwer in the 1990s started to research partition types and published (and later synchronized) partition type lists in order to help document the industry de facto standard and thereby reduce the risk of further conflicts.
Some of them also actively helped to maintain software dealing with partitions to work with the updated lists, indicated conflicts, devised additional detection methods and work-arounds for vendors, or engaged in coordinating new non-conflictive partition type assignments as well.
This type was specially reserved for individual use as part of the Alternative OS Development Partition Standard (AODPS) initiative since 2002.
[2] This is a list of known master boot record partition types on IBM PC compatible computers: