2.1.3.1.1.20.26 Property: UID

  • Article

RFC Reference: [RFC2445] section 4.8.4.7

Number of Instances Allowed: 0, 1

Format: Text ([RFC2445] section 4.3.11)

Brief Description: Provides a globally unique identifier for the appointment.

Importing to Calendar objects

There are two supported forms of textual representation of the UID property. The Augmented Backus-Naur Form (ABNF) syntax, as specified in [RFC5234], for this value is shown in the following example.

 UID = EncodedGlobalId / ThirdPartyGlobalId
  
 EncodedGlobalId        = Header GlobalIdData
 ThirdPartyGlobalId     = 1*UTF8-octets     ; Assuming UTF-8 is the encoding
  
 Header = ByteArrayID InstanceDate CreationDateTime Padding DataSize
  
 ByteArrayID           = "040000008200E00074C5B7101A82E008"
 InstanceDate          = InstanceYear InstanceMonth InstanceDay
 InstanceYear          = 4*4HEXDIG     ; UInt16
 InstanceMonth         = 2*2HEXDIG     ; UInt8
 InstanceDay           = 2*2HEXDIG     ; UInt8
 CreationDateTime      = FileTime 
 FileTime              = 16*16HEXDIG     ; UInt64
 Padding               = 16*16HEXDIG     ; "0000000000000000" recommended
 DataSize              = 8*8HEXDIG     ; UInt32 little-endian
 GlobalIdData          = 2*HEXDIG
  
 UTF8-octets = *( UTF8-char )
 UTF8-char   = UTF8-1 / UTF8-2 / UTF8-3 / UTF8-4
 UTF8-1      = %x00-7F
 UTF8-2      = %xC2-DF UTF8-tail
 UTF8-3      = %xE0 %xA0-BF UTF8-tail / %xE1-EC 2( UTF8-tail ) /
               %xED %x80-9F UTF8-tail / %xEE-EF 2( UTF8-tail )
 UTF8-4      = %xF0 %x90-BF 2( UTF8-tail ) / %xF1-F3 3( UTF8-tail ) /
               %xF4 %x80-8F 2( UTF8-tail )
 UTF8-tail   = %x80-BF
  
 

To be of type EncodedGlobalId, the value of the UID property MUST satisfy the following constraints:

  • Every character MUST be a HEXDIG.

  • The length of the string MUST be eighty-two (82) characters or more.

  • The length of the string MUST be evenly divisible by 2.

  • The first thirty-two characters MUST match (case insensitive)<203> "040000008200E00074C5B7101A82E008".

Otherwise, the UID property is of type ThirdPartyGlobalId.

If the UID is of type EncodedGlobalId, then the data MUST be decoded to its binary representation (every two HEXDIGs compose one byte).

A temporary variable EffectiveInstanceDate is defined as follows:

  • If the UID is of type EncodedGlobalId and if the InstanceDate portion of the UID is a valid date in the range of January 1st, 1601 to December 31st, 4500 (inclusive), then the EffectiveInstanceDate is the ThirdPartyGlobalId portion of the UID.

  • If the UID is of type EncodedGlobalId but the ThirdPartyGlobalId portion of the UID is not a valid date in the range of January 1st, 1601 to December 31st, 4500 (inclusive), then the EffectiveInstanceDate is the date from the RECURRENCE-ID property (in its local time zone). In the case where RECURRENCE-ID property is not present, the EffectiveInstanceDate is zero (Year = Month = Day = 0).

  • If the UID is of type ThirdPartyGlobalId, then the EffectiveInstanceDate is the date from the RECURRENCE-ID property (in its local time zone). In the case where RECURRENCE-ID property is not present, the EffectiveInstanceDate is zero (Year = Month = Day = 0).

If the UID is of type EncodedGlobalId, it MUST be imported into PidLidGlobalObjectId as specified below. The PidLidGlobalObjectId structure is specified in [MS-OXOCAL] section 2.2.1.27.

  • The Byte Array ID field MUST be set to: 0x04, 0x00, 0x00, 0x00, 0x82, 0x00, 0xE0, 0x00, 0x74, 0xC5, 0xB7, 0x10, 0x1A, 0x82, 0xE0, 0x08.

  • The YH field MUST be set to the high byte of the EffectiveInstanceDate's year.

  • The YL field MUST be set to the low byte of the EffectiveInstanceDate's year.

  • The M field MUST be set to the value of the EffectiveInstanceDate's month.

  • The D field MUST be set to the value of the EffectiveInstanceDate's day.

  • The Creation Time field MUST be set to the CreationDateTime value.

  • The X field MUST be set to the Padding value.

  • The Size field MUST be set to the DataSize value.

  • The Data field MUST be set to the binary value of GlobalIdData.

If the UID is of type EncodedGlobalId, it MUST also be imported into PidLidCleanGlobalObjectId ([MS-OXPROPS] section 2.57) as specified below. The PidLidCleanGlobalObjectId structure is specified in [MS-OXOCAL] section 2.2.1.28.

  • The Byte Array ID field MUST be set to: 0x04, 0x00, 0x00, 0x00, 0x82, 0x00, 0xE0, 0x00, 0x74, 0xC5, 0xB7, 0x10, 0x1A, 0x82, 0xE0, 0x08.

  • The YH field MUST be set to 0x00.

  • The YL field MUST be set to 0x00.

  • The M field MUST be set to 0x00.

  • The D field MUST be set to 0x00.

  • The Creation Time field MUST be set to the CreationDateTime value.

  • The X field MUST be set to the Padding value.

  • The Size field MUST be set to the DataSize value.

  • The Data field MUST be set to the binary value of GlobalIdData.

If the UID is of type ThirdPartyGlobalId, it MUST be imported into PidLidGlobalObjectId as specified below.

  • The Byte Array ID field MUST be set to: 0x04, 0x00, 0x00, 0x00, 0x82, 0x00, 0xE0, 0x00, 0x74, 0xC5, 0xB7, 0x10, 0x1A, 0x82, 0xE0, 0x08.

  • The YH field MUST be set to the high byte of the EffectiveInstanceDate's year.

  • The YL field MUST be set to the low byte of the EffectiveInstanceDate's year.

  • The M field MUST be set to the value of the EffectiveInstanceDate's month.

  • The D field MUST be set to the value of the EffectiveInstanceDate's day.

  • The Creation Time field MUST be set to 0x0000000000000000.

  • The X field MUST be set to 0x0000000000000000.

  • The Size field MUST be set to the number of OCTETS in ThirdPartyGlobalId (UTF-8 encoded length) + 0x0000000C.

  • The Data field MUST be set to the following bytes: 0x76, 0x43, 0x61, 0x6C, 0x2D, 0x55, 0x69, 0x64, 0x01, 0x00, 0x00, 0x00, followed by the value of ThirdPartyGlobalId (encoded in UTF-8).

If the UID is of type ThirdPartyGlobalId, it MUST also be imported into PidLidCleanGlobalObjectId as specified below.

  • The Byte Array ID field MUST be set to: 0x04, 0x00, 0x00, 0x00, 0x82, 0x00, 0xE0, 0x00, 0x74, 0xC5, 0xB7, 0x10, 0x1A, 0x82, 0xE0, 0x08.

  • The YH field MUST be set to 0x00.

  • The YL field MUST be set to 0x00.

  • The M field MUST be set to 0x00.

  • The D field MUST be set to 0x00.

  • The Creation Time field MUST be set to 0x0000000000000000.

  • The X field MUST be set to 0x0000000000000000.

  • The Size field MUST be set to the number of OCTETS in ThirdPartyGlobalId (UTF-8 encoded length) + 0x0000000C.

  • The Data field MUST be set to the following bytes: 0x76, 0x43, 0x61, 0x6C, 0x2D, 0x55, 0x69, 0x64, 0x01, 0x00, 0x00, 0x00, followed by the value of ThirdPartyGlobalId (encoded in UTF-8).

Exporting from Calendar objects

If the Data field of PidLidGlobalObjectId begins with the following 12 bytes: 0x76, 0x43, 0x61, 0x6C, 0x2D, 0x55, 0x69, 0x64, 0x01, 0x00, 0x00, 0x00, the remainder of the Data field (starting at the 13th byte) MUST be treated as a UTF-8 encoded string and exported directly as the UID property.

Otherwise, a modified copy of PidLidGlobalObjectId, with the YH, YL, M, and D fields set to 0x00, MUST be encoded as a hexadecimal string, and exported as the UID property.