AD: which attributes are stored in the global catalog?
The Global Catalog (GC) doesn’t store all attributes. Refer to http://support.microsoft.com/kb/256938 for all default GC attributes in Windows 2000 Active Directory.
You can easily check if an attribute is stored in the GC using ADExplorer or ADSIEdit. Look in the schema naming context and check if partialAttributeSet=TRUE.