Full text search index:

If you enable full text search capabilities for Winhelp (HLP) files the help compiler will generate a full-text search index for the help file and the Find tab in the Winhelp viewer will be populated the first time the user selects it.

The only advantage of this is that your users will not be prompted to generate the index the first time they open the help. On modern computers generating the index is completed almost instantaneously and users are used to doing it, so you can speed up compiling and reduce your distribution file size by turning this option off.

Include...

Self-explanatory options for the full-text search feature in Winhelp.

Citation:

When users copy and paste text from a Winhelp help file this text is automatically included at the top of the pasted text. You can use it for a copyright notice or any other information you want to display when your uses paste text.

You can also use the text entered here anywhere in your project by using the <%CITATION%> variable. See Using Variables for details.

Encoding of topic anchors:

Winhelp treats anchors in topics as absolute IDs that have the same status as topic IDs. If anchor IDs were used on their own it would theoretically be possible to have an anchor ID that was identical to an existing topic ID, and this would cause problems.

To ensure that an anchor is always unique Help & Manual generates a new ID for anchors by combining the topic ID and the anchor ID, separating the two with a colon (:) by default.

This is suitable for most situations. If you need a different encoding, you may either select a different separator (an underscore or a dot).

Alternatively you can choose the last option: Use anchor ID without topic ID.  This option encodes the anchor IDs as they are and assumes that they are unique and do not conflict with topic IDs. Note that Help & Manual does not check for duplicates so you use this option at your own risk.

Export A-keywords as:

By default Help & Manual generates A-keywords as A-footnotes in the temporary RTF file used to generate the Winhelp output. This is the default value for Winhelp and if you don't know what it is for please do not change this setting.

If you do need to change it you can enter any footnote character you like here for the A-keywords. (See the documentation of Microsoft Help Workshop if you need more information on this subject.)

Limit images to 256 colors:

The Winhelp viewer has an uncorrected bug that can cause the viewer to hang or crash on computers with a display that has limited color depth if the help file contains images with more than 256 colors.

This option automatically reduces all images to 256 colors to prevent these crashes. Using it is strongly recommended since you have no control over the display configuration on your users' computers!