As discussed in the Creating Multisite Applications chapter, the siteIds property on certain repository items (such as product and sku items) is defined as a context membership property. Context membership is used by internal querying mechanisms of the repository to determine whether specific items are associated with specific sites. Context membership properties are specified in the item descriptor definitions. For example:

<item-descriptor name="product" context-membership-property="siteIds" ...>

By default, the value of a siteIds context membership property can be a collection of string IDs of a single item type (typically siteConfiguration). For example, the value of a product item’s siteIds property might be:

siteIds=[homeSite,apparelSite,bargainSite]

To allow context membership properties to hold IDs of multiple Site Repository item types, including other site configuration types and site group types, set the multiItemTypeMembershipsEnabled property of the SiteMembershipManager component to true:

multiItemTypeMembershipsEnabled=true

If multiItemTypeMembershipsEnabled is true, SiteMembershipManager prepends strings to the item ID values in siteIds properties to distinguish between different item types. The strings it prepends are specified using the prefixToItemDescriptorNameMap property. This property is a Map whose keys are the prefix strings and whose values are the corresponding item types in the Site Repository.

The default value of prefixToItemDescriptorNameMap is:

prefixToItemDescriptorNameMap=\
      sg=siteGroup

Note that no prefix is needed for the siteConfiguration item type. So, for example, the value of the siteIds property of a product might be:

siteIds=[homeSite,sg:siteGroupMA]

If you add new subtypes of the touchpoint or siteGroup item type to the Site Repository and multiItemTypeMembershipsEnabled is true, you need to add prefixes to the prefixToItemDescriptorNameMap property for the new item types. For example, if you add a storeConfiguration item type and a storeGroup item type, you might set prefixToItemDescriptorNameMap to:

prefixToItemDescriptorNameMap=\
      sg=siteGroup,
      st=storeConfiguration,
      stg=storeGroup