As the categories are in a default SharePoint list you can use out-of-the-box features of Sharepoint to import the categories from external systems. Starting with V2.0 there is an additional import feature on application level included.
On Taxonomy Administration site at Management Center click on "Browse" and select the XML file to be imported from your local computer. Afterwards click on "Upload". The file will be imported asynchronously. The same structure as for exports is being used.
The structure is quite simple: All root-categories are nested under the element TaxonomyRoot and their respective children are nested within the parents element Taxonomy.
Sample:
<?xml version="1.0" encoding="utf-8"?>
<TaxonomyRoot CreateDate="2/10/2009" CreatedBy="SharepartXXL Taxonomy Extension">
<Taxonomy Name="Our Company" Synonyms="Company, Sharepart XXL" CategorizationRules="" CategorizationThreshold="80" Description="this is our Company" AZIndex="True" Navigation="True" Assignable="True" SortOrder="0">
<Taxonomy Name="Department" Synonyms="" CategorizationRules="dep*" CategorizationThreshold="75" Description="grouping the departments" AZIndex="True" Navigation="True" Assignable="True" SortOrder="0">
<Taxonomy Name="Sales" Synonyms="Sales,marketing,PR" CategorizationRules="(Sales OR Marketing)" CategorizationThreshold="70" Description="" AZIndex="True" Navigation="True" Assignable="True" SortOrder="0" />
</Taxonomy>
</Taxonomy>
<Taxonomy Name="Our Products" Synonyms="Product,Part,Solution" CategorizationRules="(Product OR Part OR Solut*)" CategorizationThreshold="50" Description="these are our products" AZIndex="True" Navigation="True" Assignable="True" SortOrder="0">
<Taxonomy Name="Newsletter" Synonyms="" CategorizationRules="" CategorizationThreshold="75" Description="" AZIndex="True" Navigation="True" Assignable="True" SortOrder="0" />
<Taxonomy Name="Taxonomy Extension" Synonyms="" CategorizationRules="" CategorizationThreshold="75" Description="" AZIndex="True" Navigation="True" Assignable="True" SortOrder="0" />
</Taxonomy>
</TaxonomyRoot>
If you want to update your existing categories please export the categories first.
In the root element you will see there is a new attribute: "ListGUID" added and every element gets an ID (ID of item in Categories list)
How the taxonomy is affected by imports
Only the categories from the root-trees occuring at the importfile will be changed.
Example: you have 3 root-tree, one each for rooms, products and customers.
If you import the product-tree only the other two trees will left unchanged. Any existing category from the product-tree that doesn't appear in the importfile will be deleted. The categories will usually be identified by it's name and their position within the tree will be changed according to their appearance within the importfile. The properties will be changed according to the values of the importfile.
If you import the product-tree and the customers-tree only the room-tree will left unchanged while the other two trees will be changed in the same manner as at the first example.