Help Link Markup
In Microsoft Help 2, link markup is used to create links between one or more topics in a compiled Help (.HxS) file or between separate Help files. There are three types of links you can add to a Help topic, as follows:
Standard HTML links.
XLinks that display link text, and can display a list of associated topics when they are clicked.
KTable links that display an list of keyword-associated links. These resemble XLinks, except that they display a list of links when the topic page loads.
Microsoft Help 2 XLinks and KTable links provide the same functionality as the ALinks and Related Topics links of previous Help versions, and look and behave like standard HTML hyperlinks. However, they have some additional authoring requirements and share a useful characteristic that sets them apart from standard HTML links: If no topic can be found to match a keyword specified in the link, no link is displayed. If no topics are found, the XLink is displayed without link formatting, and the KTable just does not appear. This behavior acts as a safeguard against dead links, and does so in a manner that is transparent to the user.
The behavior of each XLink or KTable depends on which type of index it is used with. An index can be structured to enable one-to-many relationships, in that one topic can have one or more keywords that can be shared with other topics. This is how a keyword index operates. Conversely, one-to-one linking relationships can be enforced by using an associative index. In this case, each topic can have only one unique keyword that is not used by any other topics.
Adding Help links to a topic consists of the following steps:
Declaring the MSHelp XML namespace in the <html> tag for the topic, as follows:
Adding a link to the cascading style sheet (.css) file, as follows:
<link rel="stylesheet" type="text/css" href="ms-help://Hx/HxRuntime/HxLink.css">
To add a standard HTML link to a topic, just add the link markup. For details, see HTML Link Markup.