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A COMPUTER SYSTEM FOR MANAGING LINKS AID A METHOD
IMPLEMENTING SAID SYSTEM
The present application claims priority from Frexlch
application No. 98 04660 of April 15, 1998 which is
incorporated herein by reference.
The present invention relates mainly to a computer
system for managing links, in particular hypertext links,
and to a method implementing such a system.
The network of networks~ the INTERNET, provides
IO Col~,ti1'luous iz~tez'connection between computer networks, and
is experiencing Ever greater success due, in part, to the ;
ease with which the network can be accessed via a
temporary connection, in particular a te7.ephone link to a
computer connected to the INTERNET and belonging to a
suppJ.~.ex of access or "provider', and in part to the ease
with which it is possible to search for information
described in the page description language HI'~L within a
subset of the INTERNET known as the world WidE Web or
~twww"- Pages described in the HTML language are --
2Q interpreted and displayed by browser software, in
particular by Nd~.VZGAT012~ from NETSCPiPE or INTERNET
~P~dRER~ from MICROSOFT. Each I~ERNET computer has a
permanent or temporary address I1~ that is made up of a
run of digits separated by dots. Nevertheless, to make a
connection via the INTERNET to a "web server" computer ---
that has pages for display in the HTML language, all a
user needs to know is its domain z~ame which is normally
made up of a string of characters of the type: ,._
http://www.xxx.com/
It is INTERNET that transcodes domain names into the
corresponding TP addresses. Similarly, each document on
the web is identified by a character string known as a
universal resource locator Qr 'tuRLT'.
For example:
http://www.xxx.com/abc/other/mypage.html
corresponds to the URL of a page entitled mypage, which
is described in HTML, and which is situat~:d in the
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subdirectory other of the directory abc of the web server
www.xxx_eom_
The web makes browsing easy and user-friendly by the
presence cf links which, on being selected, in particuJ.ax~
by clicking on them in a page described in the HTML
language, enable various actions to be performed:
go to a page (to a bookmark);
- g4 to another page of the same document (same
server, internal links?;
1o ~ send messages to a box for receiving e-ma~,l; or
go to a page of a different web server (external
link) _
An external Link to the default page of the
subdireetory other Qf the directory abc of the server
www.xxx.com is written as follows in the FiTML language:
ca href = "http://www.xxx.com/abc/other/"~
By default, links appear on an HTML page as
underlined blue text. ~rhis text incorporated in the code
for the page and following the link is terminated by the --
character string:
~ca/~
ether presentations can be declared (such as other
colors, images, etc.j. when passing aver a link, the
cursor changes into a drawing representing a hand
pointing upwards.
This browsing technique zn which the user need not
know and a fortiori need not key in URLs, makes the web
remarkably user-friendly. Nevertheless, if a link points
to an erroneous address, then an undesired page is
34 ~lisplaxed, while if the URL of the link is not valid,
then error 404 of the HTxP protocol occurs and a message
of the following type is displayed:
FILE NOT FOUND
The requested URL/xyz.htm was not found. on this
server.
Exceptionally, such an error comes from an erroY in
the TJR~ as input for the link, but more commonly, the
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error arises because the URL points to d page that has
subsequently been moved ar deleted. The :Link is said to
be 'Tbroken~~. while browsing, the appearance of such a
message is particularly unfriendly. This zs part~,o,~7,axly
S true for external links where the person responsible for
the web site or "webmaster'r does not have a tool fox
verifying that links are consistent and is not
necessarily informed when the addresses of pages pointed
to by the la.nks axe changed. To remedy this problem,
to proposals have been made to replace links by invax~,ant
symbolic names known as universal resource names or URNS.
One or mare name servers would translate invariant URNS
into URLs. Thus, only the name server(S) would knOW the
physical location of the documents, thereby avoiding such
15 informat7.oxi being stored redundantly by all servers
making use of them. The name server would be easy to
update. Such a solution has never been adopted on the
INTERNET because it suffers from numerous draWbackS.
Firstly, to connect to a site, it would be necessary --
20 initially to connect to the name server, which would
double the number of connections, and consequently double
the time recluired to obtain the desired information. In
addition, the name server would be interrogated by very
many web servers and would give rise to a very severe _
25 bottleneck penalty in the transmission of information.
PITKOW: "Suppox't~.ng Ghe web: a distributed hyperlink
database system", Computer Networks and ISDN Systems,
Vol. 28, No. 11, May 199, pages 981-991, describes
incorporating an "Atlas server" in a web server fox
30 communicating with other "Atlas servers~~ incorporated in
other web servers to inform them about page changes.
Thus, each web server must have an "At7.as server". In
contrast, the system of the present invention can have a
single link server operating with a very large number of
35 web servers.
Consequently, an abject of the present invention is
to provide a computer system making it possible to avail
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broken links appearing, particularly on the world wide
Web.
Another object of the present invention is to
pxovxde such a sxstem while genexat~.ng only a small
amount of traffic on the network.
Another abject of the present invention is to
provide a system that operates very reliably.
Another object of the present is to provide a system
for updating the bookmarks that specify favorite sites in
7.0 tkr.e browser softwaxe of individual cpnsultation stations.
'these objects are achieved by a computer system of
the present invention having a link change sez~rer which
collects information about pages, in particular in the
HTML language and containing links, preferably external
links, and about changes to the addresses of pages and
about the deletion of pages. when a page is modif~,ed ox'
deleted, the link change server informs the web servers
concerned that are specifying the old addresses of the
pages. -
Advantageously, information about pages containing
links is collected in co-operation with tk~e web server
hosting the pages.
Advantageously, the notified change is executed
automatically on the server hosting the page containing
the link to be modified.
The present invention will he better understood frpm
the following description and the accompanying figures
given as non-limiting examples, and in which:
~ Figure 1 is a diagram of a few computers connected
to the INTERNET and includirig valid links;
~ Figure 2 is a similar diagram of the computers
after some pf the links have been mpdified;
Figure 3 is a flow chart showing hew axe ~~ernitter't
module serves to keep track of the links under
surveillance;
Figure 4 is a flow chart of a process for
receiving a link change notification;
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Figure 5 is a flow chart of the pxocess for
receiving notification of uRL modifications; and
Figure 6 is a flow chart of a module for receiving
notification of a change of U1~L.
5 In Figures 1 to 6, the same references are used to
designate the same Elements.
In Figures 7, and 2, there can be seen three web
servers 7., 3, and 5 connected by means of the INTERNET 7
to a link server 9, a convt~ritional type of consultation
station 17., and a consultation station 13 in accordance
with the present invent-on.
The pages usually published on the web are described
in the HTML language and are defined firstly by the name
and the location of the files stored on the server, and
secondly, optionally, by a title which is incorporated in
the code of tk~e page with the tag title>. The server 7.
gives access t0 pages 2.1, 1.2, 1.3, 1.4, and 1.5 which
are described in the HTML language, far example.
The server 3 gives access to pages 3.1, 3.2, and --
3_3, e.g. described in the HTML language. The server 5
gives access to pages 5.1, 5.z, and 5.3, e.g. described
in the HTML laxzguage .
Nevertheless, it should be understood that the
present invention is not limited in any way to using the ,
HTML language, but applies to any description of eonter~t
that enables links to be created, in particular hypertext
links, e.g, by using the following page dE=scriptiori '~-
languages: SGML, XML, DHTML, ~Sp, the FiYPERCARDC~ software :"-
from APPLE, or software for managing documentation.
The page 1.1 has a first link 15.1 for going to the
top of the page without using scroll bars. A link 15.2
points to the page 1.3. The links 15.1 and 7.5.2 are
internal links whioh are relatively easy t:o manage.
Firstly site-creation software can incorporate a tool for
managing the consistency of internal links. secondly,
all of the pages 1.1 to 1.s are normally under the
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responsibility of a single person, the webmaster of web
server 1.
A link 15.3 points form page 1.1 to the bottom of
page 3.2 of server 3. A link 15.4 pdirits from page 1.1
to page 3.1 of server 3. A link 15.5 points from page
1.Z to page 5-3 of server 5. The links 15.3 to 15.5 are
external links insofar as they poinC to pages stored on
servers other than the server 1 hosting the page 1.1. A
user using a consultation station 11, typically a
microcomputer with browser software for consulting pages,
such as INTERNET EXPLORER, for example, can connect to :,
tk~e server 1 and cause the page 1.i to be displayed on
the station. ~rhe Links 15.1 to 15.5 make it easier to .-
browse through the information.
Other links, not shown, can point to ime~ges, to JAVA
applets, etc. A link pointing to the image me.gzf in
director~r abe of server www.xxx. com is written in I3TriIL as
follows:
<img source = ~~http://www.XXX.oom/abc/me.gif"~ -
Hy clicking on one of the links, the user changes
page or position on a par3e and does so without kri~WiYlg,
and without having to key in, the URLs of the various
pages desj~gnated, by the links 7,5.~ to 15.5, and without
knowing the bookmark pointed to by the link I5.1. This
situation can be disrupted, as shown in Figure 2, by
certain pages as designated by the links, in particular
the external links, either disappearing or else moving_ ~-
Indeed, tk~e J.oCations of Certain pages on web servers are ,.,
kept unchanged solely to avoid breaking links Chat
designate those pages. The server where these pages are
hosted can evolve but the webmaster freezes its structure
to avoid breaking links.
In the example of Figure 2, the link 15.3 is broken
because page 3.2 has been deleted. 'fhe contents of page
5.3 has been moved to page 5.1 of the wel~ server 5. The
content of page 3.1 has been moved to page 5.5 of web
servex 5.
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Thus, a user of consultation station 11 connected to
the ZNTERNE'f will suffer disturbance to a consultation
unless the links Z5.3, 15.4, and X5.5 axe updated. Such
updating is not easy, insofar as the webmasters of
computers 3 and 5 cannot, without lengthy searching orz
the web, find out which links point to pages hbsted on
their own servers.
In the present invention, a list of .links is ,
generated and is kept up to.date so tk~at in the event of
1o a page being modified or deleted (servers 3 and 5) an
alert is issued to the server (Z) that has links pointing _
to the pages that have been moved Or that rio lodger
exist.
After eorrectioz~, the J.~,nk 15.3 in Figure 2 is
z5 referenced 15.3. After correction, the link 15.~ zz~
Figure 2 is referenced 25.4'. After correction, the link
15_5 in Figure 2 is referenced 15.5'. After Correction,
the link 1.5.6 in Figure 2 is referenced 15.5.
In the preferred example of the present invention, a
20 link server 9 stores and keeps up to date the list of
external links on th2 INTERNET, and in particular on the
world wide web. If there is a change in a pointed-to
page, the server alerts the servers concerned that have
links pointing to said page. Advantageously, the list is
25 ge~exate~l and/or updated in co-operative manner with web
servers declaring pages that have been created, modified,
destroyed, or moved, and also pages pointed to by the ~ '-
links in the pages they host. This co-operation is
particularly important for servers with restricted
30 access, in particular with INTRANET servers or servers
requiring an access password that makes its impossible for
a computer robot to explore the pages and consequently
extract the links of the pages hosted. zn a variant
embodiment, the browser software iri consultation stations
35 Z3 also makes declarations to the link server 9 about
favorite sites or bookmarks for consultation on the web,
possibly together with their own e-mail addresses. In
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the event of a change in the address of a site ox of
pages at a site, the server 9 informs the consultation
stations 13 having browser software in accordance with
the present invention of the updates they need to make,
or in the event of a direct connection to tk~e sexvex~ 9,
it makes those changes.
For example, consultation station 13 has a shortcut
15.6 to page 3.1 of web server 3. After being notified
by the lxz~k server 9, the shortcut 15.6' of consultation
station 13 points to page 5-5 of web server 5.
However, the same link 15.6 to page 3.1 in a
consultation station 11 of conventional type is riot
automatically modified arid consequently points to a page
that is no longer relevant.
J-5 In a variant, on detecting a broken link (H'fTP error
404), the browser software does not d~.splay the
associated messages, but connects to the link server 9 to
read the new address of the pointed-to page. 7Cn this
way, the link server 9 is consulted only for broken -
links, thereby limiting traffic on the IN~.CERNET 7.
Advantageousl~r, the computer system of the present
invention includes: a module for sending out informatiozz
about the installed links on the various web servers, as
shown in Figure 3; a link server 9 provided with a module
far receiving information about links, as shown in Figure -
r
a mpd~,~,]~e for acquiring or receiving information about
modifications to pages on the various web servers, as
F_
shown in Figure 5; and receiver modules as shown in ~-
Figure 6, advantageously distributed over the various web
servers for receiving information concerrii.ng modified
pages pointed to by the links of the receiver server.
The receiver module of Figure 3 has a step 1.6 of
storing a difference file or D file showing the history
of modifications to page addresses. rn a variant, any
modification to a page (deletion, moving) is immediately
notified to the link server 9 without waiting for the L!
file to be generated by scanning all of the pages hosted
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in a search for links to be pxocessed. The scan is
preferably limited to external links. Go to 17.
Scanning step 17 consists, for example, in searching
through the code of the pages for a character string of
the following type:
<a href = protocol://server/directory/file>
where:
protocol designates the protocol used, e.g. HTTP;
server designates the address or the designation of
the hosting server;
directory designates the'directory and any ;
subdirectories in which the code file is stored; and
file designates the name of the code file forming
the page.
Go to 19.
At 19, the list at instant ~ is drawn up of all of
the links to be processed (in particular external links).
The list i_ also contains zogical locations
corresponding to the various HTML pages. --
GO to 21.
At 21, a check is made to see whethez° an earlier
list exists.
If so. g4 to 23.
Tf not, go to 25.
At 23, the present list (list i.) is compared with '-
the preceding list Mist i-1) and the difference is
I
_
stored in a difference or D file.
Go to 27.
At 25, the pxesent list (list i) is stored in the
difference or D file.
Go to 27.
At 27, the O list is sent to the link server 9. In
a variant, the A list, optionally together with a more or
less complete history of changes to the various pages
hosted by the sexver, is made available for consultation
via the TI~'~ERNET.
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~y way of example, the D list has: page-addition
messages concerning pages that have been newly added;
page-modification messages concerning pages that have
been renamed or moved; page-deletion messages concerning
5 pages that have been deleted; Link-addition messages
concerning newly created external links; link-
modification messages about links that have been
modified; and link-deletion messages concerning links
that have been deleted. For example, the sexwex 3 alerts
to the link server that the page 3.2 has been deleted and
that the page 3.1 has been modified, while web server 5
indicates that pages 5.1 and 5_3 have been modified and
that pages 5.4 and 5.5 have been added. ;-.
Transmission 27 can take place by e-mail, and the
procedure can take place automatically or after the
webmaster has validated the sender to verify that the
notification to the link server 9 is consistent, correct.
and does not contain confidential information.
TransmxssiQn can also be performed using the network --
transmission protocol TCP/IP, in particular on
interrogation of the web server by the link server 9.
Transmission 27 can also be performed by a high
level protocol of the HTTP type. For example, the link
server 9 connects to the web server and executes.,a
standard script, e.g. using the standard known as common
gateway interface or "CGI" and advantageously executes a
script which is preferably written in the PEAL language
which is particularly optimised for manipulating
arbitrary character strings. The script displays the
list of the Q file which is recovered by the link server
9. The link server 9 visits all of the web servers that
declare they include a sender module. The D file zs
advantageously deleted on the web server.
More generally, transmission 27 can be performed
using any protocol that can be understood by the
destination, e.g. voice synthesis, fax, a message on a
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pager or on a Short Message System (SMS) sent to the
webmaster of the server concerned:
Figures 4 and 5 show how the link server 9 operates.
At 29, the server receijres D files by e-mail, by
TCF/IF mode transmission, or by HTTP mode transmission.
Co to 31.
,At 31, the J,~,nk server 9 updates the link database
32, in particular concerning extErnal linlcs on the World
wide Web. In a variant, it also receives declarations of
bookmarks or favorites from browser software iri stations
13 of the present invention..
At 33 (Figure 5) the link server receives
notifications of modifications to the URLs of web pages. .-
The information about these modifications can be included
I5 in the D files, or it can be stored and transmitted
separately.
In a variant, in non-co-operative mode, the link
sexwex ~ scans tl~e various web servers to draw up the
list of web pages, their locations, and the links they --
contain. The list can also be drawn up from the rNTFiT
iridexing databass established by search engines and
including an index of links_ The web server 9
advantageously allocates a compact signature to the page.
This signature includes the tag atitle> in HTML wages,
preferably together with pertinent data for identifying
the page and based an occurrences of words, images, page
layout used, and/or by semantic analysis of the text or a
E__
checksum, i.e. the possibly weighted value of the sum of .,
the values of the characters making up the page, so as to
make it easier to identify pages that have been moved.
1n a variant, the server 1 hosting pages that have
external links 15.3 to 15.5 ~7ointing to pages 3.1, 3.2,
and 5.3 hosted by other web servers 3 and 5 notifies them
of the existence of said links and of their content. In
x'etux'r1, a server 3, 5 Qn moving a page 3.1 or 5.1 or on
deleting a page 3.2 notifies these changes to Ghe servers
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that have informed them that they are hosting pages with
links pointing to the modified pages.
Go to 35.
At 35, the link server s scans the link base to
establish a list of any links that are affected by pages
that have been changed or deleted, i.e. the list of pages
that includes lznks that are now broken.
Go to 37.
At 37, the J.ink' server 9 notifies page
z0 modifications, moves, or deletions to the web servers
that have broken links.
This notification can likewise be performed by e-
mail, n9tifiCatipn in TCP/IP transmission mode, in HTTP
type transmission mode, ete.
The operation of a notified web server 1 is shown in
Figure 5.
At 39, the server i receives notification concerning
Changes to the URLs of pages designated b_y the links 15.3
to 15.5. __
Go to 41.
At 41, the webmaster advantageously validates the
proposed modifications. If validation fails, go to 43.
Validation may fail because of uncertainty about the
origin of a message xecezved at 3~, or about its .
~5 relevance.
If validation succeeds, go to 45.
At 45, the uRLs in the HTML pages 1.1 concerned are
modified_ The program ends at 43.
The sender and receiver modules on the various
servers 7., 3, or 5 eaz~ be zmp~,emented periodically by
being triggered manually by the webmaster, paxt~.cularly
after pages have been modified, or else they can operate
as a background task, being activated iri partiCUlar in
the event of HTML pages being modified. Far e~rample,
with a server operating under the UNIXC~7 operating sy6tem,
these modules can be constituted by programs known as
DAEMONS, whereas an servers operating u~.dex~ the WINDOWS
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NT~ operating system, they can be modules known as
SERvZCES.
Advantageously, in combined co-operative and non-co
operative mode, the robot that oxawls over the World Wide
web to build a database concerning the UR~s of TiTML pages
and the links they contain, avoids exploring eo-operative
servers that have notified a ~ list.
In a vaxiant, where a server 3 or 5 modifies ~r
deletes a page, it makes a connection to the link ser~r'er
1o 9 to inquire from the list of servers 1 including pages
1.1 having links 15.3. 15.x, and 15.5 pointiz~g to a page
that has been modified, and it itself makes the _
notifications to the sex~rer 1.
It oan be extremely advantageous to provide the
system of the present. invention with security devices
preventing wrong notification, in particular malicious
notifications and/or attempts to create uridesix'ed links.
Any security system of conventional type can be used, in
i paxticular for authenticating the sender of a message and -
the integrity of its contents. By way of example,
messages can be encrypted, e.g. wit.h so-called l~public
key" encrypting algorithms such as RSA or DSA, PGP or
PGP/Mine or 5/~ime protocols. Cryptographic systems
based on public keys are described in particular in
US-A-4 204 770, US A-4 218 582, US-A-4 405 829,
US-A-4 424 414, and US-.Fr--~ 995 092, and also in the book
"Applied cryptography", second edition, by Bruce
Schneier.
In a variant, it is also possible to use a callback
mechanism_ The server calls back the Sender of the
message with an incorporated authentication random
number. The reply includes the random number or a number
that is derived from the authentication random number.
The preferred embodiment of the present i~vantion
takes account of the fact that the webmaster of a web
site, in particular of a small web site, often has a
local copy of the site in a computer or workstation that
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is not permanently connected to the INTERNET. In
contrast, the server of the web site is permanently
connected thereto. Modifications to pages in the local
copy are uploaded to the web server proper, e.g. using
the FTP protocol. Under such circumstances, the
webmaster loads client software on the computer that has
the local copy of the site for the purpose of co-
operating with the link server 9.
The webmaster registers with the link server 9 by
1o gi~ring the address of the web site (e. g.:
http://www.myserver.com or possibly d subdirectory if the
site is shared http://www.aserver.com/mydirectory/) and .
its e-mail address (e . g. myname(~myserver. com) .
This takes place either directly by filliz~g a foam
1S on the web site of the link server 9, or by configuring
the client software.
zn a first variant embodiment, the list of pairs
(link location, link) is drawn up by the client software
which looks through aJ.J, of tk~e fiJ,es contained in the --
~0 local copy of the site and extracts the tags of the
language used, in particular ~zTMZ~, that correspond to
links. For each link found, the client software cxeates
a new entry in the list, including the address which the
page tk~at i.z~cludes the 1 ink has on the web server proper, _
25 and associated with the value of the link Qnca the list
has been drawn up, the client software connects to the
link server 9, e.g, wia an HTTP protocol and its ~
..
transmits the list o~ pairs (location of link, link), _
rn the preferred embodiment, the client software
30 establishes solely a list of pages on its own site and
registers it in the link server 9. To d4 this, the
client software looks through all of the files contained
in the local copy of the site and connects to the link
server 9 via, for example, the HTTP protocol, passing the
35 address of the pages looked through in parameters.
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zf the connection to the link server 9 is working,
the file is copied into a ~~Deltae (0) directory, for
subsequent use for comparison purposes.
The link servers connect themselves in HTTP to the
5 pages registered in this way and look through them
searching for external links. Any external links found
are added to the link base under the reference of the web
site of user 3.
'floe link server continuously monitors all of the
10 registered links beJ.onging to nQn-registered servers that
make connections via HTTP.
once a link has been detected as being broken or .
moved, and regardless of whether this is by the link ,-
server 9 performing direct detection or by notification
15 of another user via the link server 9, an electronic
message is senC to the user 3 requesting synchronization
with the link server.
The webmaster 3 who receives a notification message
requesting synchronization uses the client software to -
24 connect in HTTP to the link server. The date of the most
recent update of tkie "client.~~ is passed a:~ a parameter
during the connection, and all modifications later than
said date and relating to the current site are
transmitted to the "client" in HTNIL format.
2~ The client software interprets the HTML code
returned in the preceding step and applies the
corresponding modifications tQ the local copy of the
_._
files of the site. zt does this either by deleting the
links (for deleted pages) or by replacing the links (for
30 pages that have moved), and it does so after validatiot'1
by the webmaster.
The webmaster works on the local copy of the site
deleting, adding, movit~g, ox modifying the content of its
pages.
35 The webmaster updates the web site proper which is
permanently conrieCted to the INTERNET by copying the
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local copy of the files to the site proper (e.g. via
FTP) .
The webmaster uses the client software to specify
all of the c~-~.anges that apply to the site.
The software detects pages that have been added,
deleted, moved, or modified by making a comparison
between the "Delta" (Q) directory and the local copy of
the site.
This information can be verified and modified by the
webmaster.
The client software connects tv the link server 9 in
HTTP to inform it about the modifications.
Advantageously, the link servex verifies the
validity of the information transmitted in the preceding
1S step by connecting in HTTP via the INTERNET to the
webmaster's site. Tk~e pages that have been modified or
added are looked through to determine ti~ezx external
links. Far pages that have been moved, it is verified
that the old page na longer exists and that the new page -
does indeed exist. Fox pages that have been deleted, it
is verified that the old page no longer exists.
The purpose of thi$ step is to avoid information
being falsified and to avoid the risks of if1-i.r~tentioned
false notifications. ,
Once the information has been validated, the link r-
base is looked through and the sites concerned 1, 11, 13
ax'e noti~~,ed by electronic mail.
In a variant, the webmaster can registex directly ---
from the web site proper which is permanently connected
to the INTERNET and aari recei~re notifications thereat.
Nevertheless, it should be understood that the
server 9 can also detect when pages are moved and deleted
on servers that are not registered with tile link server
9. Under such circumstances, it is assumed that the
internal coherence of each web site is properly managed,
i.e. that internal links are updated i.n the event of a
page being moved within the web site.
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The web site is looked through to find an internal
link to the page painted to by the external link which it
might be desired to oorrect subsequently. The addresses
of the page containing said internal link is stored as is
the content of the link.
When the page that zs pointed to no longer exists
(HTTP error 404), a COriri~CtiOri iS made Containing the
internal link and the new address pointed to by said link
is determined. Since the internal link will logically
already have been updated by the webmaster o~ the site,
the new address of the page is thus obtained, thereby
resolving the external link. The address pointed to by ,
the corrected internal link is notified as a aorrevted
external link to the pages of other web servers that
include an external link equal to the old internal link.
The present invention applies to any computer system
that has Links, and in particular external Links, such as
document management systems, local networks, bulletin
boards. -
The present invention applies mainly to pages that
include links on the World Wide WeH.
L
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