Useful. As practitioners, we can’t be content to paint within the lines drawn by managers. We must have the courage and creativity to ask whether our products and systems are useful, and to apply our deep knowledge of craft and medium to define innovative solutions that are more useful.

Usable. Ease of use remains vital, and yet the interface-centered methods and perspectives of human-computer interaction do not address all dimensions of web design. In short, usability is necessary but not sufficient.

Desirable. Our quest for efficiency must be tempered by an appreciation for the power and value of image, identity, brand, and other elements of emotional design.

Findable. We must strive to design navigable web sites and locatable objects, so users can find what they need.

Accessible. Just as our buildings have elevators and ramps, our web sites should be accessible to people with disabilities (more than 10% of the population). Today, it’s good business and the ethical thing to do. Eventually, it will become the law.

Credible. Thanks to the Web Credibility Project, we’re beginning to understand the design elements that influence whether users trust and believe what we tell them.

Valuable. Our sites must deliver value to our sponsors. For non-profits, the user experience must advance the mission. With for-profits, it must contribute to the bottom line and improve customer satisfaction.

Strive for consistency.

• Keep action sequences consistent in similar situations.
• Use identical terminology in prompts, menus, and help screens.
• Employ consistent commands throughout.

Enable frequent users to use shortcuts.

• As the frequency of use increases, so do the user’s desires to increase
  interaction speed.
• Abbreviations, function keys, hidden commands, and macro facilities are very
  helpful to an expert user

Offer informative feedback.

• System feedback should be provided for every operator action.
• Frequent and minor actions can provide a modest response, while the response
  should be more substantial for infrequent and major actions.

Design dialog to yield closure.

• Organized sequences of actions into groups with a beginning, middle, and end.
• Informative feedback when a group of actions is completed, gives the
  operators a sense of accomplishment and an indication that they can proceed to
  the next group of actions.

Offer simple error handling.

• The system should be designed so the user cannot make a serious error.
• If an error is made, the system should be able to detect the error and offer
  simple, comprehensible ways to recover from the error.

Permit easy reversal of actions.

• If the user knows that errors can be undone, they are encouraged to explore
  unfamiliar options without undue anxiety.
• The units of reversibility may be a single action, a data entry, or a complete
  group of actions.

Support internal locus of control.

• Experienced operators like to sense that they are in control of the system and
  that the system responds to their actions.
• Design the system to make users the initiators of actions rather than the
  responders.

Reduce short-term memory load.

• Displays should be kept simple and sufficient training time should be allotted
  for codes, mnemonics, and sequences of actions.

“a broad concept that refers to how easy it is for users to learn a system, how efficiently they can use it once they have learned to use it, and how pleasant it is to use.”

5 attributes of Usability:

1. Learnability: The user should be able to promptly start performing their tasks with the system.

2. Efficiency: Once the user has learned the system, a high level of productivity should be possible.

3. Memorability: The casual user should be able to return to the system after not having used it for some time, without having to relearn everything.

4. Errors: Users should not make many errors using the system, and if they do, they should be able to easily recover from them. Catastrophic errors should not occur.

5. Satisfaction: Users should like using the system and should be subjectively satisfied when using it. The system should be pleasant to use.

Eye-Tracking

Eye tracking is the process of measuring either the point of gaze (”where we are looking”) or the motion of an eye relative to the head. eye tracking monitor records every eye movement and highlights the most active areas on the site visually. Eye-tracking studies can help to estimate how comfortable web users are with the web-site they’re browsing through and how quickly they can understand the structure and system behind it. You can find some interesting usability findings from recent eye-tracking study.

Fold

The fold is defined as the lowest point where a web-site is no longer visible on the screen. The position of the fold is, of course, defined by the screen resolution of your visitor. The region above the fold (also called screenful) describes the region of a page that is visible without scrolling. Since the fold is seen directly without scrolling, it is often considered as the area which guarantees the highest possible ad click rates and revenues. However, Fold area isn’t that important.

Foveal viewport (Foveal area)

The fovea, a part of human’s eye, is responsible for sharp central vision, which is necessary in humans for reading, watching television or movies, driving, and any activity where visual detail is of primary importance. Foveal area is a small wide space area where your eyes are aimed at and it is the only area where you can perceive the maximum level of detail. Foveal area is a tight area of about two degrees of visual field or two thumbnails held in front of your eyes. This is the place where you’d like to deliver the most important messages of your visitors.

Foveal viewport is important, because outside of this wide screen area how your visitors see your web-pages change dramatically. Inside this area is the only part of your vision with the maximal resolution – only here no eye scanning is necessary.

Gloss

Gloss is an automated action that provides hints and summary information on where the link refers to and where it will take the user once it’s clicked. Hints can be provided via title-attribute of links. From the usability point of view users want to have the full control over everything what is happening on a web-site; clear and precise explanations of internal and outgoing links, supported by sound anchor text, can improve the usability of a web-site.

Graceful Degradation (Fault-tolerance)

Graceful Degradation is the property of a web-site to present its content and its basic features even if some of its components (partly or at all) can’t be displayed or used. In practice it means that web-sites display their content in every possible “fault” scenario and can be used in every configuration (browser, plug-ins, connection, OS etc.) the visitor might have. “Power-users” are still offered a full, enhanced version of the page. For instance, it’s typical to offer alternatives for Multimedia-content (for instance image) to ensure that the content can be perceived if images can’t be displayed.

Granularity

Granularity is the degree to which a large, usually complex data set or information has been broken down into smaller units.

Hotspot

Hotspots are clickable site areas which change their form or/and outer appearance once they are clicked. This is typical for :focus-effects when a link or any other site element is clicked.

Legibility

Legibility indicates how clear the text is visually.

Minesweeping

Minesweeping stands for user interactions which aim to identify the links on a web-site. In most cases minesweeping is a clear alarm signal for usability problems. Usually minesweeping involves the user rapidly moving the cursor or pointer over a page, watching to see where the cursor or pointer changes to indicate the presence of a link.

Mystery-Meat Navigation (MMN)

In Web mystery-meat navigation describes designs in which it is extremely difficult for users to recognize the destinations of navigational hyperlinks — or determine where the hyperlinks are.

Physical consistency

This concept describes the consistent outer appearance of a web-site – e.g. the position of logos, navigation, the use of graphic elements and typography. Physical consistency is essential for better orientation and effective site navigation.

Progressive Enhancement (PE)

Progressive Enhancement is a design strategy in which sites are created in a layered fashion — from the basic functionality for all browsers to the additional, enhanced features for modern browsers. The main advantage of progressive enhancement lies in its “universal usability” — i.e. the fact that it allows everyone to access the basic content and functionality of a web page, using any browser or Internet connection, while also providing those with better bandwidth or more advanced browser software an enhanced version of the page.

Readability

Readability describes the degree to which the meaning of text is understandable, based on the complexity of sentences and the difficulty of vocabulary. Indexes for readability usually rank usability by the age or grade level required for someone to be able to readily understand a reading passage. Readability is not legibility.

User-centered design (UCD)

User-centered design is a design philosophy in which users, their needs, interests and behavior define the foundation of web-site in terms of site structure, navigation and obtaining the information. UCD is considered as a standard approach for modern web-applications, particularly due to the rise of user generated content. In Web 2.0 visitors have to be motivated to participate and therefore need conditions optimized for their needs.

Vigilance (sustained attention)

Vigilance is the ability to sustain attention during prolonged, monotonous tasks such as proofreading a text looking for spelling errors, reminding of appointments, auto-saving word processor documents etc. In modern web-applications vigilance tasks are performed in background, automatically and thus improve the usability of the service.

Walk-Up-And-Use Design

A Walk-up-and-use design is self-explanatory and intuitive, so that first-time or one-time users can use it effectively without any prior introduction or training.

Wireframe

A wireframe is a basic structure — skeleton — of a site that describes the ideas, concepts and site structure of a web-site. Wireframes can be designed as presentations which explain to the stake holders how the site is designed, which functionality it offers and how users can accomplish their tasks. Wireframes usually don’t have any visual elements or a complete page layouts; they are often first drafts and sketches designers create on paper. Example? Here you go.

1	24-7 Co.,Ltd.
2	A-SIT
3	Academia Sinica
4	ACCESS Co., Ltd.
5	ACORD Corporation
6	Adesis Netlife S.L.
7	Adobe Systems Inc.
8	Adomo, Inc.
9	Afilias Limited
10	Agfa-Gevaert N. V.
11	AgileDelta, Inc.
12	Akmin
13	Alcatel-Lucent
14	Alisys Software
15	Altova GmbH
16	Alzheimer Research Forum Foundation
17	Amadeus s.a.s.
18	AME Info FZ LLC
19	ANCOSO Business Technologies AG
20	ANDANZA TECHNOLOGIES
21	ANEC European Association for the Co-ordination of Consumer Representation in Standardisation
22	Antenna House, Inc.
23	AOL LLC
24	Apple, Inc.
25	Argo Interactive Ltd
26	ARTSTAFF CO., LTD.
27	Asemantics S.R.L.
28	Aspect Communications
29	AstraZeneca
30	AT&T
31	Atal Behari Vajpayee – Indian Institute of Information Technology and Management, Gwalior
32	Athens Information Technology (AIT)
33	Australian Government Information Management Office (AGIMO)
34	Avaya Communications
35	Axway Software
36	Ayuntamiento de Zaragoza
37	Bango.net Limited
38	Bartimeus – Accessibility
39	BEA Systems, Inc.
40	Beihang University
41	Beijing University of Technology
42	Betfair Limited
43	BeVocal, Inc.
44	Bhrigus Software (India) Private Limited
45	Bitstream, Inc.
46	BlueNote Networks
47	BoaB interactive Pty Ltd
48	The Boeing Company
49	University of Bologna
50	Brainstage Research, Inc.
51	Brand-Zen
52	University of Bristol
53	British Broadcasting Corporation
54	BT
55	Budapest University of Technology and Economics
56	Bytemobile, Inc.
57	CA
58	California State University, Long Beach
59	Canon, Inc.
60	Cantata Technology, Inc.
61	Cape Clear Software, Inc.
62	Center for Democracy and Technology
63	CWI
64	Centre for Development of Advanced Computing (CDAC)
65	Centre Virtuel de la Connaissance sur l’Europe
66	Centro Europeo de Estudios y Formación Empresarial Garrigues
67	Centro de Treinamento iLearn
68	Cerebra
69	CERN
70	ChangingWorlds Ltd.
71	Chevron
72	China Electronics Standardization Institute
73	Chinese Academy of Sciences
74	Chinese University of Hong Kong
75	Chirurgie Portal
76	CINECA
77	Cisco
78	Citigroup
79	Clark & Parsia LLC
80	Cleveland Clinic
81	Clinical and Biomedical Computing Ltd
82	CNR–Consiglio Nazionale delle Ricerche
83	Coalition for Networked Information
84	College of Computer and Software Engineering in Taiyuan University of Technology (TYUT)
85	CommerceNet
86	Competence Centre for Interoperable Metadata (KIM) / Kompetenzzentrum Interoperable Metadaten (KIM)
87	Computas AS
88	Comverse Technology
89	Consumer Reports WebWatch
90	Cordys
91	Corticon Technologies, Inc.
92	Creative Commons
93	CSI-Piemonte
94	CSIRO
95	CSP s.c.a.r.l.
96	Daimler Chrysler Research and Technology
97	DAISY Consortium
98	Data Recovery Software
99	DataDirect Technologies
100	Defense Information Systems Agency (DISA)
101	Department of Informatics, PUC-Rio
102	Department of Information and Communication Technology – University of Trento
103	Department of Information Technology, Government of India
104	Deque Systems, Inc.
105	DERI Galway at the National University of Ireland, Galway, Ireland
106	Design Science, Inc.
107	Deutsche Telekom AG, T-Com
108	DigiCert SSL Certificate Authority
109	Digital Harbor Incorporated
110	Digital Media Institute, Tampere University of Technology
111	digital-moon Co.,Ltd
112	DIGITALSCAPE
113	Dipartimento di Informatica, Università degli Studi di Pisa
114	Disruptive Innovations
115	DOMAIN UNION
116	Dot Com Infoway
117	Dow Jones & Company
118	Dreamlab Technologies AG
119	Drutt Corporation
120	Duke University
121	Ecole Mohammadia d’Ingenieurs Rabat (EMI)
122	Ecole Polytechnique Fédérale de Lausanne (EPFL)
123	University of Edinburgh
124	Eindhoven University of Technology
125	Electronic Data Systems (EDS)
126	Electronics and Telecommunications Research Institute (ETRI)
127	Eli Lilly and Company
128	Harry Ellis
129	elmundo.es
130	EMC Corporation
131	empolis GmbH
132	Enigmatec Corporation
133	ENISA (European Network and Information and Security Agency)
134	ENLASO Corporation
135	EnvoyWorldWide
136	ERICSSON
137	examotion GmbH
138	Expway
139	Fair Isaac Corporation
140	FinanzNachrichten.de
141	FLWOR Foundation
142	Fondazione Bruno Kessler
143	Forschungszentrum Informatik (FZI)
144	Fortent
145	Fotosearch Stock Photography and Footage
146	Foundation for Research and Technology – Hellas(FORTH)
147	France Telecom
148	Fraunhofer Gesellschaft
149	Free University of Bozen-Bolzano
150	FSTC (Financial Services Technology Consortium)
151	Fujitsu Limited
152	Fundación CTIC (Centro Tecnológico para el Desarrollo en Asturias de las Tecnologías de la Información y la Comunicación)
153	Fundación ONCE
154	Futuver Consulting
155	Garlik
156	Genesys Telecommunications Laboratories
157	The George Washington University
158	German Research Center for Artificial Intelligence (DFKI) Gmbh
159	Gijón City Council
160	Go Daddy.com
161	Google, Inc.
162	GoWare, Inc.
163	Groupe des Ecoles de Télécommunications
164	Grupointermark 96, S.L.
165	Guangzhou Middleware Research Center
166	Health Level Seven, Inc.
167	The Hebrew University of Jerusalem
168	Helsinki University of Technology
169	HP
170	High Performance Technologies, Inc.
171	HiSoftware Inc.
172	Hitachi, Ltd.
173	HOB GmbH & Co. KG
174	Hong Kong Applied Science and Technology Research Institute Co., Ltd. (ASTRI)
175	Hutchison 3G
176	IBBT
177	IBM Corporation
178	ICONIX, Inc.
179	iFLYTEK
180	Ikivo AB
181	IKM Internet Kaufmarkt GmbH
182	ILOG, S.A.
183	Image, Video and Multimedia Systems Lab (IVML-NTUA)
184	IMG SRC, Inc.
185	Indus Net Technologies
186	Industrial Technology Research Institute (ITRI)
187	InfoComm Development Authority of Singapore (iDA Singapore)
188	InfoGin Ltd.
189	Infopark AG
190	Infoteria Corporation
191	Infraware, Inc.
192	Innodata Isogen, Inc.
193	INNOVIMAX
194	Institut National de Recherche en Informatique et en Automatique (INRIA)
195	Institute of Informatics & Telecommunications (IIT), NCSR
196	Integrated Forum on Electronic Commerce (ECIF)
197	Intel Corporation
198	Intelink Management Office (IMO)
199	International Webmasters Association / HTML Writers Guild (IWA-HWG)
200	Internet Academy, Inc.
201	Internet Association Japan (IA Japan)
202	Internet Content Rating Association
203	Internet Technology Research Committee (ITRC)
204	Interoperability Technology Association for Information Processing, Japan
205	Intervoice, Inc.
206	Inventive Designers n.v.
207	IONA Technologies, Inc.
208	ISeC
209	Istituto per la Ricerca, la Formazione e la Riabiltazione – Onlus (I.Ri.Fo.R.)
210	Ivis Group Limited
211	Jataayu Software
212	JBoss Inc.
213	Joint Info. Systems Comm. of the UK Higher Ed. Funding Council (JISC)
214	Joost Technologies BV
215	Jozef Stefan Institute
216	JustSystems Corporation
217	K-Space
218	KOPINT-DATORG Economic Research, Marketing and Computing Company Ltd.
219	Lawrence Berkeley National Laboratory
220	Layer 7 Technologies
221	LayoutBank’s Web Templates
222	Lexmark International, Inc.
223	Library of Congress
224	Lockheed Martin Corporation
225	Logistics Management Institute (LMI)
226	Loquendo, S.p.A.
227	Los Alamos National Laboratory
228	M:Metrics Ltd.
229	MacKichan Software, Inc.
230	Manufacturers’ Association for Information Technology
231	Marden Edwards Limited
232	Mark Logic Corporation
233	Mathematical Association of America
234	McDonald Bradley, Inc.
235	Meraka Institute
236	Merck & Co., Inc.
237	Metatomix inc
238	Microsoft Corporation
239	MIND Center for Interdisciplinary Informatics
240	Ministerio de Administraciones Públicas
241	MITRE Corporation
242	Mitsue-Links Co., Ltd.
243	Mobile Web 2.0 Forum
244	Mobileaware, Ltd.
245	Motorola, Inc.
246	Mozilla Foundation
247	MTA SZTAKI
248	mTLD Top Level Domain Limited
249	National Association of Convenience Stores (NACS)
250	National ICT Australia (NICTA) Ltd
251	National Information-society Agency (NIA)
252	National Institute of Advanced Industrial Science and Technology (AIST)
253	National Institute of Standards and Technology (NIST)
254	National Internet Development Agency of Korea
255	National Research Council Canada
256	NeoMtel
257	Netzwelt.de
258	New Zealand State Services Commission
259	Nexaweb Technologies, Inc.
260	NexTag, Inc.
261	Nextstage Corporation
262	NIC.br – Brazilian Network Information Center
263	Nippon Telegraph & Telephone Corp. (NTT)
264	Nokia
265	Nominet
266	Nortel Networks
267	Novarra, Inc.
268	NRCD Research Institute (National Rehabilitation Center for Person with Disabilities)
269	NTT DoCoMo
270	Nuance Communications, Inc.
271	OASIS (Organization for the Advancement of Structured Information Standards)
272	Object Management Group, Inc. (OMG)
273	Objective Systems, Inc.
274	OCLC (Online Computer Library Center, Inc.)
275	Office of the Government Chief Information Officer (OGCIO)
276	Ontology Works
277	Ontopia AS
278	Open Geospatial Consortium
279	The Open University
280	OpenLink Software Inc.
281	Openstream, Inc.
282	Openwave Systems Inc.
283	Opera Software
284	Oracle Corporation
285	Orbeon, Inc.
286	Ordnance Survey
287	Origo Services Limited
288	OSS Nokalva, Inc.
289	Oxford Brookes University
290	Page Traffic Web-Tech (P) Ltd.
291	Parkyeri
292	Partners HealthCare System, Inc.
293	Pfizer Inc
294	PicoForms
295	PINT, Inc. (Powell Internet)
296	Pitney Bowes, Inc.
297	Pixel Trader Ltd.
298	Presidenza del Consiglio dei Ministri
299	Profium Ltd.
300	Progeny Systems
301	Progress Software
302	Prometheo
303	PTC-Arbortext
304	Queensland University of Technology
305	Quickoffice Inc
306	Raining Data Corporation
307	RealNetworks
308	Entidad pública empresarial Red.es
309	RenderX
310	Rensselaer Polytechnic Institute
311	Research Academic Computer Technology Institute (CTI)
312	Research In Motion, Ltd. (RIM)
313	REWERSE
314	Rogue Wave Software
315	Royal National Institute for the Blind (RNIB)
316	Royal Website Design
317	RuleSpace, LLC
318	Samsung Electronics Co., Ltd.
319	SandCherry, Inc.
320	Sandpiper Software, Inc.
321	SAP AG
322	SATEC (Sistemas Avanzados de Tecnología, S.A.)
323	SBsquared Limited
324	Science Commons (Creative Commons)
325	Search Engine Optimization Inc.
326	Seeburger AG
327	seekXL
328	Segala
329	Seiko Epson Corporation
330	SEMANTIC SYSTEMS, S.A.
331	Semantic Universe
332	Seresco, S.A.
333	Sevenval AG
334	SGKP
335	Sharp Corporation
336	ShopWiki
337	SICS
338	Siderean Software, Inc.
339	Siemens AG
340	SinnerSchrader Deutschland GmbH
341	SIZ Informatikzentrum der Sparkassenorganisation GmbH
342	SK Telecom
343	SKYARC System Corporation
344	Sociedad Asturiana de Diversificación Minera S.A. (SADIM S.A.)
345	Society for Technical Communication (STC)
346	Sociomedia, Inc.
347	Software & Information Industry Association (SIIA)
348	Software AG
349	Sogei (Societa Generale D’Informatica)
350	Sonoa Systems, Inc.
351	University of Southampton
352	Sozon Inc.
353	SRI International
354	SS8 Networks, Inc.
355	Stadt Branchenbuch GmbH
356	Stanford University
357	STFC (Science & Technology Facilities Council)
358	Streamezzo
359	Suchmaschinenoptimierung Sebcom
360	Sun Microsystems, Inc.
361	SURF net bv
362	Swiss Federal Institute of Technology (ETH Zürich)
363	Symbian Limited
364	Syncro Soft
365	Syntellect Inc.
366	Systinet Inc.
367	Talis Information Limited
368	Tarari Incorporated
369	Teleca Sweden AB
370	TeleCable de Asturias S.A.U.
371	Telecom Italia SpA
372	Telefónica de España, SAU
373	Tellme Networks
374	Teranode Corporation
375	ThinkCo Ltd
376	Third Party Formations Limited t/a The Company Warehouse
377	Thunderhead Ltd.
378	TIBCO Software, Inc.
379	TNO Telecon
380	Top4Office
381	TopQuadrant
382	Toshiba Corporation
383	Tradelink Electronic Commerce Limited
384	Transera Communications, Inc.
385	TSSG
386	U-Turn Media Group
387	Uncover the Net Web Directory
388	United States Environmental Protection Agency (EPA)
389	Universidad de Castilla-La Mancha
390	Universidad de Oviedo
391	Universidad Politécnica de Madrid
392	Universitat Politècnica de Catalunya
393	Université catholique de Louvain
394	University of Aberdeen, Computing Science
395	University of Amsterdam
396	University of Helsinki
397	University of Innsbruck
398	University of Kent
399	University of Manchester
400	University of Oxford
401	University of Southern California Information Sciences Institute (USC / ISI)
402	University of Sunderland
403	V-Enable, Inc.
404	Verascape
405	VeriSign, Inc.
406	Vertica
407	Viaden
408	Vignette Corporation
409	Vishwak Solutions Pvt. Ltd.
410	Vision Australia
411	Vitria Technology, Inc.
412	Vocalocity, Inc.
413	Vodafone
414	VoiceObjects AG
415	VoiceSignal Technologies, Inc.
416	Volantis Systems Ltd
417	Voxeo Corporation
418	Voxpilot Ltd.
419	Vrije Universiteit
420	Walt Disney Internet Group
421	Waterloo Maple Inc.
422	Web3D Consortium
423	Webexcel Solutions Limited
424	webMethods, Inc.
425	WebSoft International, Inc.
426	WGBH National Center for Accessible Media
427	Wright State University
428	WSO2
429	Wyzen Systems Private Limited
430	X-Hive Corporation B.V.
431	Xandros Corporation
432	Xerox Corporation
433	Yahoo!, Inc.
434	ZERO Factory, Inc.

HTML	Hypertext Markup language
XHTML	Extensible Hypertext Markup language
XML	Extensible Markup Language
DHTML	Dynamic Hypertext Markup language
SGML	Standard Generalized Markup Language
XML-DTD	XML – Document Type Definition.
XAML	Extensible Application Markup Language
WPF	Windows Presentation Foundation
XSLT	XSL Transformations
XSL-FO	XSL Formatting Objects
XSL	Extensible Style sheet Language
XSD	XML Schema Definition
XML DOM	XML Document Object Model
HDML	Handheld Device Markup Language
CSV	Comma Separated Values
JSON	JavaScript Object Notation
WML	Wireless Markup Language
WAP	Wireless Application Protocol
WBXML	Wireless Binary XML
SOAP	Simple Object Access Protocol
SGML	Standard Generalized Markup Language
eBXML	Electronic Business XML Initiative

Message:	Description:
100 Continue	Only a part of the request has been received by the server, but as long as it has not been rejected, the client should continue with the request
101 Switching Protocols	The server switches protocol

2xx: Successful

Message:	Description:
200 OK	The request is OK
201 Created	The request is complete, and a new resource is created
202 Accepted	The request is accepted for processing, but the processing is not complete
203 Non-authoritative Information
204 No Content
205 Reset Content
206 Partial Content

3xx: Redirection

Message:	Description:
300 Multiple Choices	A link list. The user can select a link and go to that location. Maximum five addresses
301 Moved Permanently	The requested page has moved to a new url
302 Found	The requested page has moved temporarily to a new url
303 See Other	The requested page can be found under a different url
304 Not Modified
305 Use Proxy
306 Unused	This code was used in a previous version. It is no longer used, but the code is reserved
307 Temporary Redirect	The requested page has moved temporarily to a new url

4xx: Client Error

Message:	Description:
400 Bad Request	The server did not understand the request
401 Unauthorized	The requested page needs a username and a password
402 Payment Required	You can not use this code yet
403 Forbidden	Access is forbidden to the requested page
404 Not Found	The server can not find the requested page
405 Method Not Allowed	The method specified in the request is not allowed
406 Not Acceptable	The server can only generate a response that is not accepted by the client
407 Proxy Authentication Required	You must authenticate with a proxy server before this request can be served
408 Request Timeout	The request took longer than the server was prepared to wait
409 Conflict	The request could not be completed because of a conflict
410 Gone	The requested page is no longer available
411 Length Required	The “Content-Length” is not defined. The server will not accept the request without it
412 Precondition Failed	The precondition given in the request evaluated to false by the server
413 Request Entity Too Large	The server will not accept the request, because the request entity is too large
414 Request-url Too Long	The server will not accept the request, because the url is too long. Occurs when you convert a “post” request to a “get” request with a long query information
415 Unsupported Media Type	The server will not accept the request, because the media type is not supported
416
417 Expectation Failed

5xx: Server Error

Message:	Description:
500 Internal Server Error	The request was not completed. The server met an unexpected condition
501 Not Implemented	The request was not completed. The server did not support the functionality required
502 Bad Gateway	The request was not completed. The server received an invalid response from the upstream server
503 Service Unavailable	The request was not completed. The server is temporarily overloading or down
504 Gateway Timeout	The gateway has timed out
505 HTTP Version Not Supported	The server does not support the “http protocol” version

Web 1.0	Web 2.0
DoubleClick	Google AdSense
Ofoto	Flickr
Akamai	BitTorrent
mp3.com	Napster
Britannica Online	Wikipedia
personal websites	blogging
evite	upcoming.org and EVDB
domain name speculation	search engine optimization
page views	cost per click
screen scraping	web services
publishing	participation
content management systems	wikis
directories (taxonomy)	tagging (“folksonomy”)
stickiness	syndication