A Lineage of Admin Items is the tree structure of relationships between a series of Admin Items that represent some sort of evolutionary sequence of edits. Lineages only ever comprise one type of Admin Item so each Code List exists within a Lineage of its predecessor and successor Code Lists. Contexts and Context Maps also have Lineages. However, a Lineage of, say, Code Lists will never contain Contexts or Context Maps.
Most Lineages are simple chains of Items where one Item supersedes just one another. These are created automatically through the normal process of drafting and publishing revisions:
|Code List Lineage||Context Lineage|
A few Lineages are more complex. One Item can supersede several predecessor Items (where the contents of several Items have been merged. Several Items can supersede a single predecessor Item (where one Item has been split into several separate Items).
There is also the option to express a weaker relationship than "Supersedes/Superseded By". This is the "Based on/Contributed to" relationship. Linking two Items with this relationship does not affect the Admin Status of the linked to Item.
Complex Lineages can only be created by someone with the Registrar role. Instructions are here. Here is an example of a more complex Lineage: