As the ht://Dig system will index
all HTML pages on a system, individual authors of pages may
want to control some of the aspects of the indexing
operation. To this end, ht://Dig will recognize some special
<META> tag attributes. The following things can be
controlled in this manner:
Do not index the document
Notify a user that the document has expired
Set keywords for the document
General <META> tag use
In HTML, any number of <META> tags can be used between
the <HEAD> and </HEAD> tags of a document. There
are three possible attributes in this tag, two of which are
recognized by ht://Dig:
Used to name a specific property.
Used to supply the value for a named property.
A document could start with something like the following:
The following properties are recognized by ht://Dig:
Detailed information about the htdig-email,
htdig-email-subject properties can be found in the
Email notification service
Descriptions of the properties and their values:
The value of this property should be a blank separated list
of keywords which will get a very high weight when
searching. This can be used to get around some problems
with common synonyms for words in the document. For
example, if a document is a telephone directory, possible
keywords could be "telephone phone directory book list".
Now, regardless of what text is actually in the document,
it can be found if these keywords are used in the search.
This property has no value associated with it. If it is
used, the document will NOT be included in any searches.
Example uses of this could be:
A document which is dynamic. ie: the contents change
Temporary document, not officially available, yet.
A document you just don't want to be found.
The value is the email address a notification message
should be sent to. Multiple email addresses can be given by
separating them by commas. If no email address is given, no
notification will be sent.
(Please check the Email
notification service documentation for more details on
The value is the date on or after which the notification
should be sent. The format is simply month / day /
year, or if the iso_8601
attribute is set, year - month - day.
Make sure that the year has the century with it
as well. This means that you should use 1995
instead of 95.
If no date is given, no notification will be sent. (Please
check the Email notification
service documentation for more details on this.)
The value specifies the subject the notification message.
This is an optional property. (Please check the
Email notification service
documentation for more details on this.)
The value specifies restrictions on robots (including ht://Dig)
for the current page. These restrictions can be "noindex" to
prevent indexing the document but allowing the robot to follow
links from the page, "nofollow" to allow indexing but preventing
links from being followed, or "none" to prevent
both. Additionally, ht://Dig supports the values "index" and
"follow" and "all" which obviously are the opposite of the other
values and are the default behavior. For more information on
META robots tags, check out the
HTMLAuthor's Guide to the Robots META tag.
The value allows you to specify an alternate excerpt
(description) of a page. If the config-file option
"use_meta_descrption" is used, then any documents with
descriptions will use them instead of the automatically