Directory Identifier
-
15 -
- The sum of the following shall not exceed 30:
. if there is a File Name, the length of the File Name;
. if there is a File Name Extension, the length of the File Name Extension.
7.5.2
File Identifier length
The length of the File Identifier shall be the sum of the following:
- if there is a File Name, the length of the File Name,
- if there is a File Name Extension, the length of the File Name Extension,
- the number of digits in the File Version Number,
- 2 (the number of SEPARATORS).
7.6 Directory
Identifier
7.6.1
Directory Identifier Format
A Directory Identifier shall consist of a sequence of one or more d-characters or d1-characters (see 7.4.4),
except as specified in 7.6.2.
7.6.2
Reserved Directory Identifiers
- The root directory shall be identified by a Directory Identifier consisting of a single (00) byte.
- As specified in 6.8.2.2, certain Directory Identifiers shall consist of a single (00) byte or a single (01) byte.
7.6.3
Directory Identifier length
The length of a Directory Identifier shall not exceed 31.
8 Volume
Descriptors
The Volume Descriptors shall identify the volume, the partitions recorded on the volume, the volume creator(s),
certain attributes of the volume, the location of other recorded descriptors and the version of the standard which
applies to the volume descriptor.
8.1
Format of a Volume Descriptor
BP
Field name
Content
1
Volume Descriptor Type
numerical value
2 to 6
Standard Identifier
CD001
7
Volume Descriptor Version
numerical value
8 to 2048
(Depends on Volume Descriptor Type)
(Depends on Volume Descriptor
Type)
8.1.1
Volume Descriptor Type (BP 1)
This field shall specify as an 8-bit number the Volume Descriptor Type.
Number 0
shall mean that the volume Descriptor is a Boot Record;
Number 1
shall mean that the Volume Descriptor is a Primary Volume Descriptor;
Number 2
shall mean that the Volume Descriptor is a Supplementary Volume Descriptor;
Number 3
shall mean that the Volume Descriptor is a Volume Partition Descriptor;
Numbers 4 to 254
are reserved for future standardization;
Number 255
shall mean that the Volume Descriptor is a Volume Descriptor Set Terminator.
This field shall be recorded according to 7.1.1.
8.1.2
Standard Identifier (BP 2 to 6)
This field shall specify an identification of this Standard.
