Valid Characters and Naming Rules

The use of names in The Open Group DCE often involves more than one directory service. For example, CDS interacts with either GDS or DNS to find names outside the local cell.

Note:

Because CDS, GDS and DNS all have their own valid character sets and syntax rules, the best way to avoid problems is to keep names short and simple, consisting of a minimal set of characters common to all three services. The recommended set is the letters A to Z, a to z, and the digits 0 to 9. In addition to making directory service interoperations easier, use of this subset decreases the probability that users in a heterogeneous hardware and software environment encounter problems creating and using names.

Valid Characters in CDS, GDS and DNS Names details the valid characters in CDS names, and the valid characters in GDS and DNS names as used by CDS:

• Characters in white boxes are valid in all three kinds of names.

• Characters in light shaded boxes are valid only in CDS and GDS names.

• Characters in dark shaded boxes are valid only in CDS names.

Implementations may support additional national character sets to be used in names and attribute values. However, implementations that provide for support of additional character sets may lose interoperability to other implementations that conform to this specification.

Valid Characters for GDS Naming Attributes

The character set for all other naming attributes is chosen by the user of the XDS interface. The character set is dependent on the syntax of the selected attribute:

• For printable strings, the valid characters are those that are displayed as valid characters for GDS as shown in Valid Characters in CDS, GDS and DNS Names .

• The T.61 graphical character set is specified in T.61 Syntax .

• The ISO 8859-1 (Latin-1) graphical character set is specified in ISO 8859-1 (Latin-1) Syntax .

• For numeric strings, the valid character set is 0-9 and the space character.

• For the IA5 character set, all characters with a coded representation of lower than or equal to 0x7f are valid. The GDS restricts the valid characters to range from 0x07 to 0x7f inclusive.

The default schema of GDS contains only naming attributes that specify character sets of type Printable string or T.61 graphical character set.

Country Syntax

Country Name	Code	Country Name	Code
AFGHANISTAN	AF	ALBANIA	AL
ALGERIA	DZ	AMERICAN SAMOA	AS
ANDORRA	AD	ANGOLA	AO
ANGUILLA	AI	ANTARCTICA	AQ
ANTIGUA AND BARBUDA	AG
ARGENTINA	AR	ARUBA	AW
AUSTRALIA	AU	AUSTRIA	AT
BAHAMAS	BS	BAHRAIN	BH
BANGLADESH	BD	BARBADOS	BB
BELGIUM	BE	BELIZE	BZ
BENIN	BJ	BERMUDA	BM
BHUTAN	BT	BOLIVIA	BO
BOTSWANA	BW	BOUVET ISLAND	BV
BRAZIL	BR	BRITISH INDIAN OCEAN	IO
		TERRITORY
BRUNEI DARUSSALAM	BN	BULGARIA	BG
BURKINA FASO	BF	BURMA	BU
BURUNDI	BI	BYELORUSSIAN SSR	BY
CAMEROON	CM	CANADA	CA
CAPE VERDE	CV	CAYMAN ISLANDS	KY

Country Name	Code	Country Name	Code
CENTRAL AFRICAN REPUBLIC	CF	CHAD	TD
CHILE	CL	CHINA	CN
CHRISTMAS ISLAND	CX	COCOS (KEELING)
		ISLANDS	CC
COLOMBIA	CO	COMOROS	KM
CONGO	CG	COOK ISLANDS	CK
COSTA RICA	CR	COTE D'IVOIRE	CI
CUBA	CU	CYPRUS	CY
CZECHOSLOVAKIA	CS	DENMARK	DK
DJIBOUTI	DJ	DOMINICA	DM
DOMINICAN REPUBLIC	DO	EAST TIMOR*	TP
ECUADOR	EC	EGYPT	EG
EL SALVADOR	SV	EQUATORIAL GUINEA	GQ
ETHIOPIA	ET	FALKLAND ISLANDS	FK
		(MALVINAS)
FAROE ISLANDS	FO	FIJI	FJ
FINLAND	FI	FRANCE	FR
FRENCH GUIANA	GF	FRENCH POLYNESIA	PF
FRENCH SOUTHERN	TF	GABON	GA
TERRITORIES
GAMBIA	GM	GERMAN DEMOCRATIC	DD
		REPUBLIC
GERMANY, FEDERAL	DE	GHANA	GH
REPUBLIC OF
GIBRALTAR	GI	GREECE	GR
GREENLAND	GL	GRENADA	GD
GUADELOUPE	GP	GUAM	GU
GUATEMALA	GT	GUINEA	GN
GUINEA-BISSAU	GW	GUYANA	GY
HAITI	HT	HEARD AND MC	HM
		DONALD ISLANDS
HONDURAS	HN	HONG KONG	HK
HUNGARY	HU	ICELAND	IS
INDIA	IN	INDONESIA	ID
IRAN (ISLAMIC REPUBLIC OF)	IR	IRAQ	IQ
IRELAND	IE	ISRAEL	IL
ITALY	IT	JAMAICA	JM
JAPAN	JP	JORDAN	JO
KAMPUCHEA, DEMOCRATIC	KH	KENYA	KE
KIRIBATI	KI	KOREA, DEMOCRATIC	KP
		PEOPLE'S REPUBLIC OF
KOREA, REPUBLIC OF	KR	KUWAIT	KW
LAO PEOPLE'S DEMOCRATIC	LA	LEBANON	LB
REPUBLIC
LESOTHO	LS	LIBERIA	LR
LIBYAN ARAB JAMAHIRIYA	LY	LIECHTENSTEIN	LI
LUXEMBOURG	LU	MACAU	MO
MADAGASCAR	MG	MALAWI	MW
MALAYSIA	MY	MALDIVES	MV

Country Name	Code	Country Name	Code
MALI	ML	MALTA	MT
MARSHALL ISLANDS	MH	MARTINIQUE	MQ
MAURITANIA	MR	MAURITIUS	MU
MEXICO	MX	MICRONESIA	FM
MONACO	MC	MONGOLIA	MN
MONTSERRAT	MS	MOROCCO	MA
MOZAMBIQUE	MZ	NAMIBIA	NA
NAURU	NR	NEPAL	NP
NETHERLANDS	NL	NETHERLANDS ANTILLES	AN
NEUTRAL ZONE	NT	NEW CALEDONIA	NC
NEW ZEALAND	NZ	NICARAGUA	NI
NIGER	NE	NIGERIA	NG
NIUE	NU	NORFOLK ISLAND	NF
NORTHERN MARIANA ISLANDS	MP	NORWAY	NO
OMAN	OM	PAKISTAN	PK
PALAU	PW	PANAMA	PA
PAPUA NEW GUINEA	PG	PARAGUAY	PY
PERU	PE	PHILIPPINES	PH
PITCAIRN	PN	POLAND	PL
PORTUGAL	PT	PUERTO RICO	PR
QATAR	QA	REUNION	RE
ROMANIA	RO	RWANDA	RW
ST. HELENA	SH	SAINT KITTS AND NEVIS	KN
SAINT LUCIA	LC	ST. PIERRE AND MIQUELON	PM
SAINT VINCENT AND THE	VC	SAMOA	WS
GRENADINES
SAN MARINO	SM	SAO TOME AND PRINCIPE	ST
SAUDI ARABIA	SA	SENEGAL	SN
SEYCHELLES	SC	SIERRA LEONE	SL
SINGAPORE	SG	SOLOMON ISLANDS	SB
SOMALIA	SO	SOUTH AFRICA	ZA
SPAIN	ES	SRI LANKA	LK
SUDAN	SD	SURINAME	SR
SVALBARD AND JAN	SJ
MAYEN ISLANDS
SWAZILAND	SZ	SWEDEN	SE
SWITZERLAND	CH	SYRIAN ARAB REPUBLIC	SY
TAIWAN, PROVINCE	TW	TANZANIA, UNITED	TZ
OF CHINA		REPUBLIC OF
THAILAND	TH	TOGO	TG
TOKELAU	TK	TONGA	TO
TRINIDAD AND TOBAGO	TT	TUNISIA	TN
TURKEY	TR	TURKS AND CAICOS ISLANDS	TC
TUVALU	TV	UGANDA	UG
UKRAINIAN SSR	UA	UNITED ARAB	AE
		EMIRATES
UNITED KINGDOM	GB	UNITED STATES	US

Country Name	Code	Country Name	Code
UNITED STATES MINOR	UM	URUGUAY	UY
OUTLYING ISLANDS
USSR	SU	VANUATU	VU
VATICAN CITY STATE	VA	VENEZUELA	VE
VIET NAM	VN	VIRGIN ISLANDS (BRITISH)	VG
VIRGIN ISLANDS (U.S.)	VI	WALLIS AND FUTUNA	WF
		ISLANDS
WESTERN SAHARA*	EH	YEMEN	YE
YEMEN, DEMOCRATIC	YD	YUGOSLAVIA	YU
ZAIRE	ZR	ZAMBIA	ZM
ZIMBABWE	ZW

*

Provisional name.

T.61 Syntax

The optional use of additional character repertoires is permitted and provided for, according to the CCITT T.61 specification. However, neither the composition and allocation of these character sets nor the specific conformance requirements are specified here.

Some T.61 alphabetical characters have a two-byte representation. For example, a lower-case letter a with acute accent is represented by 0xc2 (code for acute accent) followed by 0x61 (code for lower-case a).

Only certain combinations of diacritical characters and basic letters are valid. They are shown in Combinations of Diacritical Characters and Basic Letters .

The non-spacing underline (code 0xcc) must be followed by a Latin alphabetical character; that is, a basic letter (a-z or A-Z), or a valid diacritical combination.

Bold characters cannot be reverse mapped.

All characters that stand alone must be followed by a space.

ISO 8859-1 (Latin-1) Syntax

ISO 8859-1 (Latin-1) Code Set shows the valid set of ISO 8859-1 characters. (The row headings indicate the lower four bits and the column headings show the higher four bits of the encoding in hexadecimal.)

Invalid Conversions from T.61 to ISO 8859-1 Syntax

• c6 (breve)

• c7 (dot above)

• c8 (umlaut)

• ca (ring)

• cd (double accent)

• ce (ogonek)

• cf (caron)

Invalid ISO 8859-1 Combinations of Diacritical Characters and Letters shows the invalid combinations of diacritical letters when converting from the T.61 codeset to the ISO 8859-1 codeset. GDS displays a ? (question mark) when it encounters a combination that is not defined in the ISO 8859-1 codeset.

Invalid Conversions from ISO 8859-1 to T.61 Syntax

The following characters cannot be converted from ISO 8859-1 syntax to T.61 syntax; GDS generates an error when it attempts to perform the conversion:

• 5c (\)

• 7b ({)

• 7d (})

• a6 ([??])

• a9 (©)

• ac ([??])

• ad (SHY)

• ae (®)

• b9 (¹)

Metacharacters

Certain characters have special meaning to the directory services; these are known as metacharacters. Metacharacters and Their Meaning lists and explains the CDS, GDS and DNS metacharacters.

Directory
Service	Character	Meaning
CDS	/	Separates components of a name (atomic names).
	*	When used in the rightmost atomic name of a name, acts as a wildcard, matching zero or more characters.
	?	When used in the rightmost atomic name of a name, acts as a wildcard, matching exactly one character.
	\	Used where necessary in front of a / (slash), an * (asterisk) or a ? (question mark) to escape the character (indicates that the following character is not a metacharacter).
GDS	/	Separates Relative Distinguished Names (RDNs).
	,	Separates multiple attribute type/value pairs (attribute value assertions) within an RDN.
	=	Separates an attribute type and value in an attribute value assertion.
	\	Used in front of a / (slash), a , (comma) or an = (equal sign) to escape the character (indicates that the following character is not a metacharacter).
DNS	.	Separates elements of a name.

Some metacharacters are not permitted as normal characters within a name. For example, a \ (backslash) cannot be used as anything but an escape character in GDS.

Additional Rules

Summary of CDS, GDS and DNS Characteristics summarises major points about CDS, GDS and DNS character sets, metacharacters, restrictions, case-matching rules, internal storage of data, and ordering of elements in a name.

Characteristic	CDS	GDS	DNS
Character Set	a to z, A to Z, 0 to 9 plus space and special characters shown in Figure A-1	a to z, A to Z, 0 to 9 plus . : , ' + - = () ? / and space	a to z, A to Z, 0 to 9 plus . -
Metacharacters	/ * ? \	/ , = \	.
Restrictions	Atomic names cannot contain a / (slash). The first atomic name following the global cell name (or /.: prefix) cannot contain an = (equal sign). For enumeration operations, a \ (backslash) must be used to escape any * (asterisk) or ? (question mark) character in the rightmost atomic name. Otherwise (if not escaped in the rightmost atomic name), the character is interpreted as a wildcard.	Relative distinguished names cannot begin or end with a / (slash). Attribute types must begin with an alphabetic character, can contain only alphanumerics, and cannot contain spaces. An alternative method of specifying attribute types is by object identifier, a sequence of digits separated by . (dots). A \ (backslash) must be used to escape a / (slash), a , (comma), and an = (equal sign) when using them as anything other than metacharacters. Multiple consecutive unescaped instances of / (slashes), , (commas), = (equal signs) and \ (back-slashes) are not allowed. Each attribute value assertion contains exactly one unescaped = (equal sign).	The first character must be alphabetic. The first and last characters cannot be a . (dot) or a - (dash). Cell names in DNS must contain at least one . (dot); they must be more than one level deep.

Characteristic	CDS	GDS	DNS
Case-Matching Rules	Case exact	Attribute types are matched case insensitive. The case-matching rule for an attribute value can be case exact or case insensitive, depending on the rule defined for its type at the DSA.	Case insensitive
Internal Representation	Case exact	Depends on the case-matching rule defined at DSA. If the rule says case insensitive, alphabetic characters are converted to all lower-case characters. Spaces are removed regardless of the case-matching rule.	Alphabetic characters are converted to all lower-case characters.
Ordering of Name Elements	Big endian (left to right from root to lower-level names).	Big endian (left to right from root to lower-level names).	Little endian (right to left from root to lower-level names).

Maximum Name and Attribute Sizes

Maximum Sizes of Directory Service Names lists maximum sizes for Directory Service names and attributes in CDS.

Notes:

1. Implementations must support these sizes and must not exceed these limits in remote operations.

2. The defined sizes determine the actual contents of the string, not including the terminating null.

	Maximum Size
Name Type	(octets)
CDS atomic name (character string between two slashes)	254
CDS full name (including global or local prefix, cell name and slashes separating atomic names)	1023
CDS attribute name	31
CDS class name	31
GDS distinguished name	1023
DNS relative name (character string between two dots)	64
DNS fully qualified name (sum of all relative names)	255

[??] Some characters or strings that appear in the printed document are not easily representable using HTML.

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