Normally, clicking on an entry in the index of a help file executes a jump to the top of the topic containing the keyword. However, you can also associate keywords with anchors, which are jump targets in your topics. When an anchor keyword is clicked in the index the user is taken directly to the anchor location in the topic.
1.Select the Insert Anchor tool in Write > Insert Object to insert a new anchor or double-click on an anchor icon in your topic text to edit an existing anchor.
2.Type the keywords into the Keywords: field of the Anchor dialog. You can enter both main keywords and sub-keywords. Use the TAB key to enter sub-keywords (an indented keyword automatically becomes the sub-keyword of the keyword above it).
Same keywords in anchors and Topic Options:
It is possible to have the same keywords in both the topic's Topic Options and in one or more anchors in the same topic. However, if you want your index entries to enable jumps to the anchor without confusing the user it is better to avoid this.
Note that you can also add keywords to anchors by editing the keyword with the Index Tool. See Editing the index directly for details.
Anchor keywords in the Index Tool:
Normally, anchor keywords look exactly the same as other keywords in the Index Tool in Project > Tools. To make the anchor keywords visible select Expanded View at the bottom of the Index Tool window. The anchors of anchor keywords will then be displayed after their topic IDs, separated from the IDs by a # character, like this:
In the example above intro_part1 is the topic ID and beginners is the anchor name.
Anchor keywords in the Edit Keyword dialog:
Anchor keywords are always displayed in the topic_id#anchorname format in the Edit Keyword dialog, which is display by selecting the Edit tool in the Index Tool toolbar.
When the user clicks on a keyword found in multiple topics, a dialog is displayed showing the names of the topics in which the keywords are found together with the title of the help project (this is only really relevant for modular projects containing multiple help files).
In HTML Help, however, the keyword text is displayed instead of the name of the topic. This is a restriction of the HTML Help format and cannot be changed.
Both the entries found here refer to the keyword "Horticulture". The first keyword is an anchor keyword, the second is a normal keyword in a topic.
IDs, Context Numbers and Keywords (Reference)