html ico数据类型,HTML可以代替ICO的标记

Status of this document

This is a W3C Working Draft for review by W3C members and other

interested parties. It is a draft document and may be updated,

replaced or obsoleted by other documents at any time. It is

inappropriate to use W3C Working Drafts as reference material or to

cite them as other than "work in progress". A list of current W3C

tech reports can be found at:

Note: since working drafts are subject to

frequent change, you are advised to reference the above URL, rather

than the URLs for working drafts themselves.

Abstract

One of the features of HTML is that it allows authors to include

characters and symbols in the text that cannot be typed in. In

HTML2, these so-called character

entities are limited to letters with accents

and some typographic symbols. HTML doesn't yet allow character

entities for mathematical symbols and other common signs. Authors

have to resort to inline images for these. This document defines a

list of some of those `other' symbols for use in future versions of

HTML.

Contents

HTML is a simple markup language for creating hypertext documents

that are portable between platforms. A document that is marked-up

with HTML consists of a mix of data characters (the text that

appears on the screen) and mark-up (information for the application

about the function and relation of the various data parts).

Many data characters can be typed in directly: an `a' is just the

`a' key on the keyboard; for others the editor or word-processor

may have a special method to insert them: " + a = ä. If the editor

doesn't offer such a method, it may be possible to replace the

character with a bit of mark-up: type the six characters `ä'

instead of `ä' Any application that understands HTML should be able

to translate this back to the appropriate character. A keyword like

`ä' is called a character

entity (or more precise: `character entity

reference')

HTML2 defines a list of such character entities. That lists

consists of all the characters from the

so-called ISO Added Latin

1 set, plus a few of its own. This is enough

for texts in most Western languages, but it doesn't help with other

languages or mathematics. It is expected that the set will be

extended with all the characters in the ISO 10646

(a.k.a. Unicode) set, but even then there

are many common symbols that are missing.

HTML documents often contain small icons to draw attention to

interesting links or to special types of information. For example,

the existence of a sound could be indicated by an icon of a

loudspeaker. Gopher and FTP menus also use icons to indicate the

types of links they contain.

Such icons could be created with inline images, but there are

several advantages to incorporating them into future levels of the

HTML language in the form of SGML entities. In that way, they are

defined on a par with other predefined entities, such as the

ISO-defined sets of accented characters or the mathematical and

Greek symbols.

One advantage is that authors do not have to hunt around for

suitable images and create hyperlinks to them. Instead, they can

write &audio; and

be assured that all browsers will do their best to print some

likeness of a loudspeaker.

Since the entity defines only the general shape, not the exact

pixel-for-pixel image, the browser is free to choose a size and

color that matches the rest of the display. The best browsers will

have symbols in several sizes, appropriate for use in 12, 14 or 17

point text, for example.

Using entities instead of inlined images is also faster (depending

on the implementation, of course). The browser will always use the

same image for an entity, independent of the document's origin.

After a while, there will even be browsers that come with the

symbols already built-in.

Authors are free to use any symbol for whatever purpose they

choose, but like Humpty Dumpty, they will be better understood if

they do not make a symbol mean what they choose it to mean, but use

it for its commonly accepted value. The descriptions below suggest

possible semantics, but only frequent usage by many people can make

the true intention clear.

First of all, of course,

the names of the

entities are standardized.

Their intended use is also standardized, but the definitions are

kept somewhat vague on purpose. As stated above, the meaning of a

symbol is likely to evolve when it comes into common usage, until

some universally accepted meaning emerges.

The shapes

are notstandardiazed,

but the images in this document are provided as suggestions, to

give consistency across implementations. Developers of products on

specific platforms are encouraged to use the conventional icons on

that platform where they exist.

The alternative glyphs below are there mainly to show that the

shapes can be

varied.

Desriptions of the entites, with suggested renderings. The part

`[test: xxx]' shows the entity in actual use.

 [test:

&archive;]

&archive; - archive

server. A collection of (related) documents, that can be

manipulated as a single unit. When it is used in a link, it

retrieves either the whole archive or its table of

contents. Example: Tar

files, Zip files, database files.

 (or: ,

or: )

[test: &audio;]

&audio; - audio

sequence. A sound fragment, such as a piece of music or speech.

When used in a link, it will play the

sound. Example: links to

audio files in Gopher menus; the current time in a synthesized

voice.

 (or: )

[test: &binary.document;]

&binary.document; - binary

data. A document that contains data that is unreadable by

humans, and of which the precise type is not known or not

important. When used in a link, the data is downloaded, but not

displayed. Example: binary

files in Gopher menus.

 (or: ) [test: &uuencoded.document;]

&uuencoded.document; - uuencoded

document

 (or: )

[test: &binhex.document;]

&binhex.document; - binhex

format. A document that is encoded in Macintosh hexadecimal

coding. Hopefully this symbol can be phased out in the future, as

servers and client become smarter, since this is not information

that normal users are interested

in. Example: Binhex

files in Gopher menus.

 (or: ) [test: &compressed.document;]

&compressed.document; - compressed

document. A file that is compressed

with compress, gzip,

or equivalent utilities. Normally part of a link to such a

file. Example: a

compressed file in an FTP directory.

 (or: , or: )

[test: &text.document;]

&text.document; - text/plain,

html, etc.. A document containing primarily text. This includes

text with markup instructions, if the browser is (expected to be)

able to interpret them. A part of a link, it will retrieve and

display the

document. Example: a

plain text file, an HTML document, a TeX DVI file.

 (or: ) [test: &document;]

&document; - unspecified

document type. Some document, the exact type of which is

unimportant (contrast this

with &unknown.document; below). Example: a

directory listing showing files and subdirectories (folders); a

list of titles of articles, with document symbols replacing bullet

marks.

 (or: ) [test: &unknown.document;]

&unknown.document; - unrecognized

document type

 [test:

&calculator;]

&calculator; - calculator.

This symbol should give access to some sort of interactive

calculator. Example: a

calculator could be included in a form to allow people to do some

computations before they fill in the requested numbers.

 (or: , or: ) [test: &caution;]

&caution; - warning

sign. Draws attention to an important piece of information. It

is normally not used in a

link. Example: `Warning:

the next video fragment contains scenes of extreme cruelty.'

 [test:

&clock;]

&clock; - clock

or time. A clock should give access to the current time or to

the elapsed time since some

event. Example: selecting

the clock returns the simulated time in a multi-user strategy

game.

 [test:

&disk.drive;]

&disk.drive; - removable

media type. Gives access to whatever disk is in the indicated

drive. The fact that it is removable means that the contents can

change or may be absent

altogether. Example: a

link to the disk on the machine of a colleague.

 [test:

&diskette;]

&diskette; - floppy

disk. Represents a collection of files stored on a floppy disk.

In contrast to the &disk.drive; above, this is a

specific disk. Usually, access is

slow. Example: a disk in

a jukebox, a disk in a mail-order catalogue.

 [test:

&display;]

&display; - computer

screen. The computer's display as an output device. Could be

used together with the fax and the printer to let the user select

where he want something to be

printed. Example: when a

document is available in different resolutions, the display symbol

indicates that one of them version is suitable for computer

screens.

 [test: &fax;]

&fax; - facsimile

machine. A fax machine as an output device. Like the display

and printer symbols, this can be used to indicate the destination

of some

output. Example: forwarding

a message to somebody without an e-mail address can be done by

selecting the fax symbol and entering a phone number.

 [test:

&filing.cabinet;]

&filing.cabinet; - filing

cabinet. A container for documents and folders. It is usually

larger than a folder, and the contents are more

divers. Example: a link

to an FTP server.

 (or: )

[test: &film;]

&film; - film

or animation, such as MPEG movie. A timed sequence of images,

optionally with a sound track, such as a video sequence, a computer

animation, a slide show, or a live video

link. Example: a video

clip on a CD-I.

 [test:

&fixed.disk;]

&fixed.disk; - fixed

media drive. Either a container for folders and documents, or

the destination of some data. In the first case, there must be a

reason why the device is important (and therefore why the symbols

for folder or filing cabinet are not

applicable). Example: a

link to the local files on the user's own machine.

 (or: , or: ) [test: &folder;]

&folder; - folder

or directory. A container for documents and maybe other

folders. As part of a link, it should retrieve a listing of the

folder's

contents. Example: a

gopher menu, a directory.

 [test: &form;]

&form; - fill-out

form. Gives access to a fill-out form, normally coded as an

HTML

document. Example: links

to different types of tax forms.

 (or: ) [test: &ftp;]

&ftp; - ftp

server. Represents a connection using the FTP protocol, when

for some reason it is important that the user is aware of the

server's

type. Example: information

that is available over a number of channels, one of which is an FTP

connection.

 [test:

&glossary;]

&glossary; - glossary

of terms, etc. Gives access to a glossary of

terms. Example: a link

to a technical dictionary.

 [test:

&gopher;]

&gopher; - gopher

server. A connection using the Gopher

protocol. Example: an

information provider might list alternative addresses, indicating

with the gopher symbol that some of them are Gopher

connections.

 [test: &home;]

&home; - home

document. Represents the `home page' of a collection of related

nodes (not necessarily the user's own home page). Normally part of

a

hyperlink. Example: each

node in somebody's personal collection could contain a link to his

`Welcome' page.

 (or: ,

or: ,

or: )

[test: ℑ]

ℑ - photograph,

drawing or graphic of any kind. Represents a photograph,

drawing, etc. When used in a link, it retrieves the image and

displays it. Example: a

link of type I in a Gopher menu; a `submit' button in a form that

sets image parameters.

 (or: )

[test: &index;]

&index; - searchable

index. Represents an interactive index. When used in a link, it

gives access to a searchable document, which allows at least

keywords to be

entered. Example: a link

to a WAIS index over some collection of documents; a link of type 7

in a Gopher menu.

 [test: &mail;]

&mail; - e-mail

messages . Represents either a single mail

message or the mail sub-system. If the context is clear, it can

also be used as a label in front of someone's address (cf. the

telephone symbol). As part of a hyperlink, it respectively

retrieves that message or starts a (possibly integrated) mail

agent. Example: in a

view of a mailbox, each message can be prefixed with a mail

icon.

 [test:

&mail.in;]

&mail.in; - mail-in

tray. A special mail folder (viz. the one in which the mail

system deposits new messages). As a hyperlink, it displays the

contents of the folder, in the form of an index.

 [test:

&mail.out;]

&mail.out; - mail-out

tray. A special mail folder (viz. the one in which the user

stores messages that are to be sent out). Note that this

is not the folder that

keeps copies of messages that have been

sent.Example: a link to a special

directory in which the user's composed messages are collected,

until he exits the mail system (at which point the messages are

sent and the directory is emptied.)

 [test: ↦]

↦ - geographical or

schematic map. A document that consists of a map of some kind.

In a link, it retrieves the map and displays

it. Example: a road map

with instructions how to reach some building; a schematic

representation of some production process.

 [test:

&mouse;]

&mouse; - mouse/pointing

device.The mouse as an input

device. Example: label

in front of instructions that are only applicable if you have a

mouse.

 [test: ¬ebook;]

&notebook; - notes

or annotations. Indicates the presence of notes or annotations,

presumably related to the context of the icon. When part of a link,

it displays the

notes. Example: an

annotated classical text linking the commentary by means of symbols

in the margin.

 [test:

&parent;]

&parent; - parent

of current document. In a more or less hierarchical collection

of nodes, this represents the parent of the current node. Should be

used as a link to that

node. Example: a link to

the parent directory of an FTP directory.

 (or: ) [test: &next;]

&next; - next

document in current sequence.The next

document of a collection that is meant to be read in

order. Example: each

chapter of a book could end with a link to the next chapter.

 (or: )

[test: &previous;]

&previous; - previous

document in current sequence. The previous document of a

collection that is meant to be read in

order. Example: each

chapter of a book could start with a link to the previous

chapter.

 [test:

&printer;]

&printer; - hardcopy

device. A printer as an output device. (Compare with the

display and fax

symbols.) Example: ???

 [test:

&summary;]

&summary; - summary.

A summary of a document or of a collection of documents. In a link,

it retrieves the text of the

summary. Example: the

table of contents of a book could include a link to a summary.

 (or: , or: ) [test: &telnet;]

&telnet; - telnet

connection. A terminal-based connection to some service, using

the Telnet protocol. When part of a link, it should start a

terminal-emulator and a telnet connection to the indicated

service.Example: a link to a library's

on-line catalogue that still uses its own user-interface.

 [test:

&tn3270;]

&tn3270; - tn3270

terminal session. A terminal-based connection to some service,

that requires a TN3270 terminal (-emulator) to work (cf. the telnet

symbol). When part of a link, it should start a terminal-emulator

and a telnet connection to the indicated

service. Example: a link

to a database manager running on an IBM mainframe.

 [test: &toc;]

&toc; - table

of contents. A table of contents over one or more documents. As

a link, it should display the table of contents associated with the

current

document. Example: each

chapter of a hyper-book could start with a link to the book's table

of contents.

 [test:

&trash;]

&trash; - waste

paper basket

 [test:

&telephone;]

&telephone; - telephone

number. Next to a number, it indicates that the number

represents a telephone number (cf. the third meaning of the mail

symbol).

 [test:

&cd.rom;]

&cd.rom; - CD

ROM. A collection of documents contained on a read-only CD,

including music CDs. (cf. the fixed disk, disk drive, and diskette

symbols).

 [test: &cd.i;]

&cd.i - CD-I.

An interactive session with a CD-I.

 [test:

&keyboard;]

&keyboard; - keyboard

device. The keyboard as an input device (cf. mouse).

 [test: &stop;]

&stop; - error

sign. A more severe warning then the &caution;

symbol.

 [test:

&network;]

&network; - computer

network

 [test:

&smiley;]

&smiley; - happy

face. Used as postfix adjective/adverb, meaning `for fun',

`ironic', `half-serious', etc.

 [test:

&sadsmiley;]

&sadsmiley; - sad

face. Used as postfix adverb, meaning `unfortunately'

 (or: )

[test: &new;]

&new; -new! Draws

attention to something in the document that has recently been

changed and that the reader has probably not seen before.

 [test:

&play.start;]

&play.start; - play.

Play button for starting a movie or sound, as on cassette or CD

player (cf. play.stop, play.pause, play.fast.forward,

play.fast.reverse).

 [test:

&play.stop;]

&play.stop; - stop

play. Stop button for stopping a movie or sound, as on cassette

or CD player (cf. play.start, play.pause, play.fast.forward,

play.fast.reverse).

 [test:

&play.pause;]

&play.pause; - pause.

Pause button for pausing a movie or sound, as on cassette or CD

player (cf. play.start, play.stop, play.fast.forward,

play.fast.reverse).

 [test:

&play.fast.forward;]

&play.fast.forward; - fast

forward. fast-forward button for skipping along a movie or

sound, as on cassette or CD player (cf. play.stop, play.pause,

play.start, play.fast.reverse).

 [test:

&play.fast.reverse;]

&play.fast.reverse; - fast

reverse. fast reverse button for going back in a movie or

sound, as on cassette or CD player (cf. play.stop, play.pause,

play.start, play.fast.reverse).

 (or: )

[test: &work;]

&work;- work

in progress/under construction. Often added to

a document that is in a very preliminary state. (The icon is based

on the traffic sign of a road worker and a heap of sand. In

countries where the sign is unknown or looks different, the entity

may have to be displayed with a different icon.)

 [test: &www;]

&www;- The

World-Wide Web. To refer to the WWW as a

whole, to mark a URL, etc.

 [test: &html;]

&html;- HTML. Information

about HTML, mark a document as being in HTML, link to an HTML

version, etc.

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