The following definitions identify the base types that will be used in this specification.

CodeText -- a character string consisting entirely of visible characters from an implied character set. The presence of non-visible characters, even blank spaces, is an error. The length of a CodeText string is between 1 and 50 characters, inclusive. In XML environments, CodeText may not contain XML characters with special meaning. These include the ampersand (&), etc.

ShortName -- a character string consisting of visible characters from an implied character set, together with optional use of blank spaces. Any other non-visible characters are ignored during processing, and other non-visible characters are stripped out before acceptance as a value of an attribute having this datatype. The length of a ShortName string is between 1 and 50 characters, inclusive. The first and last characters must be visible characters that are not the space character.

LongName -- a character string consisting of visible characters from an implied character set, together with optional use of blank spaces. Any other non-visible characters are ignored during processing, and other non-visible characters are stripped out before acceptance as a value of an attribute having this datatype. The length of a LongName string is between 1 and 150 characters, inclusive. The first and last characters must be visible characters that are not the space character.

EmailText -- a character string consisting entirely of visible characters from an implied character set. The presence of non-visible characters, even blank spaces, is an error. The length of an EmailText string is between 1 and 50 characters, inclusive. The first and last characters must be visible characters that are not the space character.

TelephoneText -- a character string consisting of visible characters from an implied character set, together with optional use of blank spaces. Any other non-visible characters are ignored during processing, and other non-visible characters are stripped out before acceptance as a value of an attribute having this datatype. The length of a TelephoneText string is between 1 and 50 characters, inclusive. The first and last characters must be visible characters that are not the space character.

AddrLineText -- a character string consisting of visible characters from an implied character set, together with optional use of blank spaces. Any other non-visible characters are ignored during processing, and other non-visible characters are stripped out before acceptance as a value of an attribute having this datatype. The length of an AddrLineText is between 1 and 50 characters, inclusive. The first and last characters must be visible characters that are not the space character.

CommentText -- a character string consisting of visible characters from an implied character set, together with optional use of blank spaces, tab characters, and return or line feed characters. Any other non-visible characters are ignored during processing, and other non-visible characters are stripped out before acceptance as a value of an attribute having this datatype. The length of a CommentText string is between 1 and 250 characters, inclusive. The first and last characters must be visible characters that are not the space character.

DefinitionText -- a character string consisting of visible characters from an implied character set, together with optional use of blank spaces, tab characters, and return or line feed characters. Any other non-visible characters are ignored during processing, and other non-visible characters are stripped out before acceptance as a value of an attribute having this datatype. The length of a DefinitionText string is between 1 and 5000 characters, inclusive. The first and last characters must be visible characters that are not the space character.

Date -- a value that represents a calendar date, constrained by the natural rules for dates using the Gregorian calendar. A Registry will be able to respond to queries involving minimal date arithmetic, e.g. finding all instances of an entity having dates for a given attribute that fall within a given range, or finding all instances having dates in the past 30 days, or finding all registry items whose registration is scheduled to expire in the next 3 months, etc. More advanced date arithmetic or date manipulation is at the discretion of the Registry.

Date Literal -- a character string value that identifies a specific date. A date literal string is of the form YYYY-MM-DD where YYYY is an integer literal for the year, MM is an integer literal for the month of the year, and DD is an integer literal for the day of the month. Whenever a date value is presented to a user, or requested from a user, the date value is presented or transmitted as the equivalent date literal.

Datetime -- a value that represents a calendar date and a time within that date, with time precision to the minute, or finer. Unless otherwise indicated time is Universal Coordinated Time based on a 24-hour clock. A Registry has the capability to convert a Datetime type to a Date type, with the expected loss of precision. Any other datetime arithmetic or datetime manipulation is at the discretion of the Registry.

Datetime Literal -- a character string value that identifies a specific datetime. A datetime literal string is of the form YYYY-MM-DD HH:MM:SS where YYYY is an integer literal for the year, MM is an integer literal for the month of the year, DD is an integer literal for the day of the month, HH is an integer literal for the hour (assuming 24-hour clock), MM is an integer literal for the minute within the hour, and SS is an integer literal for the second within the minute. Whenever a datetime value is presented to a user, or requested from a user, the datetime value is presented or transmitted as the equivalent datetime literal.

SmallInt -- A non-negative integer with value less than 2**16.

URNref -- a character string that conforms to the format of a Uniform Resource Name (URN) as specified by IETF RFC 1241. The length of a URNref string is less than or equal to 150 characters.

(See http://www.ietf.cnri.reston.va.us/rfc/rfc2141.txt?number=2141)

URLref -- a character string that conforms to the format of a Uniform Resource Locator (URL) as specified by W3C. The length of a URLref string is less than or equal to 150 characters.

(See http://www.w3.org/Addressing/URL/5_BNF.html)

FTPref -- a character string that conforms to the format of a File Transfer Protocol (FTP) Uniform Resource Locator (URL) as specified by W3C. The default user name is "anonymous". The length of an FTPref string is less than or equal to 150 characters.

(See http://www.w3.org/Addressing/URL/5_BNF.html)

FILEref -- a character string that is a URLref or an FTPref.

MIMEtype – a character string that identifies a MIME type, as listed in the official list of all MIME media-types assigned by the IANA (Internet Assigned Number Authority). The length of a MIMEtype string is less than or equal to 150 characters.

(See ftp://ftp.isi.edu/in-notes/iana/assignments/media-types/media-types)

LanguageId-- a character string that identifies a human language and a country where that language has evolved. In general, it is of the form "xx-CC", where xx is a two character code (lowercase) for a human language and CC is a two character country code. Legal strings are specified by Language Identifier, definitions [33] through [38] in W3C XML 1.0. (http://www.w3.org/TR/REC-xml#sec-lang-tag).

CharEncoding -- a character string that identifies the encoding of a character set. It is specified by the encoding name (EncName) of an Encoding Declaration, definition [81] in W3C XML 1.0.

(http://www.w3.org/TR/REC-xml#charencoding).