PidLidCategories Canonical Property
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PidLidCategories Canonical Property

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Specifies a list of categories for an item.

Associated properties:


Property set:


Long ID (LID):


Data type:




To generate a keywords header field, clients must set the value of this property to the desired values. This property has multiple strings; each category should be mapped to a single keyword.

Multipurpose Internet Mail Extensions (MIME) writers should copy each sub-value of this property to a separate keyword in the Keywords header field, with a comma (U+002C) and space (U+0020) separating each keyword. MIME writers may drop this property instead of copying it to the keywords header field, in order to avoid conflict among different sets of categories in different organizations.

Protocol Specifications


Provides property set definition and references to related Exchange Server protocol specifications.


Converts from Internet standard e-mail conventions to message objects.

Header Files


Provides data type definitions.

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