Perceived Types (Legacy Windows Environment Features)


Windows Desktop Search 2.x is an obsolete technology that was originally available as an add-in for Windows XP and Windows Server 2003. On later releases, use Windows Search instead.

PerceivedType is a property that classifies an item in the index. This classification is different from the "kind" classification used by the Advanced Query Syntax but similarly lets users refine their search results. The AQS kind lets users limit their search query while the PerceivedType property lets users filter their result set.


Use the PerceivedType property to classify your file type so that users can filter their search results by type. The output must be one of the following strings:

  • contact
  • communications
  • communications/email
  • communications/calendar
  • communications/task
  • communications/im
  • document
  • document/note
  • document/text
  • document/spreadsheet
  • document/presentation
  • music
  • images
  • images/picture
  • images/video
  • folder
  • program

For example, when you want to create a filter add-in for a new picture file type, you need to implement the following in your IFilterinterface:

  • GetChunk to return a FULLPROPSPEC that includes: D5CDD505-2E9C-101B-9397-08002B2CF9AE/PerceivedType
  • GetValue to return a PROPVARIANT that includes: VT_LPWSTR = "images/picture"


Developing IFilter Add-ins

Developing Protocol Handlers

Advanced Query Syntax